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Bracey KM, Fye M, Cario A, Ho KH, Noguchi P, Gu G, Kaverina I. Glucose-stimulated KIF5B-driven microtubule sliding organizes microtubule networks in pancreatic β cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2023.06.25.546468. [PMID: 37425827 PMCID: PMC10327020 DOI: 10.1101/2023.06.25.546468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
In pancreatic islet β cells, molecular motors use cytoskeletal polymers microtubules as tracks for intracellular transport of insulin secretory granules. The β-cell microtubule network has a complex architecture and is non-directional, which provides insulin granules at the cell periphery for rapid secretion response, yet to avoid over-secretion and subsequent hypoglycemia. We have previously characterized a peripheral sub-membrane microtubule array, which is critical for the withdrawal of excessive insulin granules from the secretion sites. Microtubules in β cells originate at the Golgi in the cell interior, and how the peripheral array is formed is unknown. Using real-time imaging and photo-kinetics approaches in clonal mouse pancreatic β cells MIN6, we now demonstrate that kinesin KIF5B, a motor protein with a capacity to transport microtubules as cargos, slides existing microtubules to the cell periphery and aligns them to each other along the plasma membrane. Moreover, like many physiological β-cell features, microtubule sliding is facilitated by a high glucose stimulus. These new data, together with our previous report that in high glucose sub-membrane MT array is destabilized to allow for robust secretion, indicate that MT sliding is another integral part of glucose-triggered microtubule remodeling, likely replacing destabilized peripheral microtubules to prevent their loss over time and β-cell malfunction.
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2
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Fan X, Okada K, Lin H, Ori-McKenney KM, McKenney RJ. A pathological phosphorylation pattern enhances tau cooperativity on microtubules and facilitates tau filament assembly. RESEARCH SQUARE 2025:rs.3.rs-6247226. [PMID: 40297677 PMCID: PMC12036459 DOI: 10.21203/rs.3.rs-6247226/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/30/2025]
Abstract
Phosphorylation plays a crucial role in both normal and disease processes involving the microtubule-associated protein tau. Physiologically, phosphorylation regulates tau's subcellular localization within neurons and is involved in fetal development and animal hibernation. However, abnormal phosphorylation of tau is linked to the formation of neurofibrillary tangles (NFTs) in various human tauopathies. Interestingly, the patterns of tau phosphorylation are similar in both normal and abnormal processes, leaving unclear whether phosphorylated tau retains its functional role in normal processes. The relationship between tau phosphorylation and NFT assembly in tauopathies is also still debated. To address these questions, we investigated the effects of tau phosphorylation on microtubule binding, cooperative protein envelope formation, and NFT filament assembly relevant to tauopathies. Consistent with previous results, our findings show that tau phosphorylation decreases tau's overall affinity for microtubules, but we reveal that phosphorylation more dramatically impacts the cooperativity between tau molecules during tau envelope formation along microtubules. Additionally, we observed that the specific pattern of phosphorylation, rather than overall phosphorylation level, strongly impacts the assembly of tau filaments in vitro. Our results reveal new insights into how tau phosphorylation impacts tau's physiological roles on microtubules and its pathoconversion into NFTs.
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Affiliation(s)
- Xiangyu Fan
- Department of Molecular and Cellular Biology, University of California, Davis, 145 Briggs Hall, Davis, CA, United States, 95616
| | - Kyoko Okada
- Department of Molecular and Cellular Biology, University of California, Davis, 145 Briggs Hall, Davis, CA, United States, 95616
| | - Henry Lin
- Department of Molecular and Cellular Biology, University of California, Davis, 145 Briggs Hall, Davis, CA, United States, 95616
| | - Kassandra M. Ori-McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, 145 Briggs Hall, Davis, CA, United States, 95616
| | - Richard J. McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, 145 Briggs Hall, Davis, CA, United States, 95616
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3
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Markus SM. Microtubule motors of opposite polarity cooperate rather than compete in cargo transport. Nat Struct Mol Biol 2025; 32:595-597. [PMID: 40133460 PMCID: PMC12061008 DOI: 10.1038/s41594-025-01524-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2025]
Abstract
Microtubule-based cargo transport relies on the actions of dynein and kinesins, motors that walk in opposite directions yet act together to ensure appropriate distribution of cargos in cells. Research now provides mechanistic insights into how these seemingly antagonistic motors collaborate, rather than compete, to promote each other’s activities.
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Affiliation(s)
- Steven M Markus
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA.
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4
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Kirimtay K, Huang W, Sun X, Qiang L, Wang DV, Sprouse CT, Craig EM, Baas PW. Tau and MAP6 establish labile and stable domains on microtubules. iScience 2025; 28:111785. [PMID: 40040809 PMCID: PMC11879653 DOI: 10.1016/j.isci.2025.111785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2024] [Revised: 12/01/2024] [Accepted: 01/08/2025] [Indexed: 03/06/2025] Open
Abstract
We previously documented that individual microtubules in the axons of cultured juvenile rodent neurons consist of a labile domain and a stable domain and that experimental depletion of tau results in selective shortening and partial stabilization of the labile domain. After first confirming these findings in adult axons, we sought to understand the mechanism that accounts for the formation and maintenance of these microtubule domains. We found that fluorescent tau and MAP6 ectopically expressed in RFL-6 fibroblasts predominantly segregate on different microtubules or different domains on the same microtubule, with the tau-rich ones becoming more labile than in control cells and the MAP6-rich ones being more stable than in control cells. These and other experimental findings, which we studied further using computational modeling with tunable parameters, indicate that these two MAPs do not merely bind to pre-existing stable and labile domains but actually create stable and labile domains on microtubules.
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Affiliation(s)
- Koray Kirimtay
- Department Neurobiology and Anatomy, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Wenqiang Huang
- Department Neurobiology and Anatomy, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Xiaohuan Sun
- Department Neurobiology and Anatomy, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Liang Qiang
- Department Neurobiology and Anatomy, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Dong V. Wang
- Department Neurobiology and Anatomy, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA
| | - Calvin T. Sprouse
- Department Physics, Central Washington University, Ellensburg, WA 98926, USA
| | - Erin M. Craig
- Department Physics, Central Washington University, Ellensburg, WA 98926, USA
| | - Peter W. Baas
- Department Neurobiology and Anatomy, Drexel University, 2900 Queen Lane, Philadelphia, PA 19129, USA
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5
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Sahabandu N, Okada K, Khan A, Elnatan D, Starr DA, Ori-McKenney KM, Luxton G, McKenney RJ. Active microtubule-actin cross-talk mediated by a nesprin-2G-kinesin complex. SCIENCE ADVANCES 2025; 11:eadq4726. [PMID: 39982998 PMCID: PMC11844729 DOI: 10.1126/sciadv.adq4726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Accepted: 01/22/2025] [Indexed: 02/23/2025]
Abstract
Nesprin-2 Giant (N2G) is a large integral membrane protein that physically connects the nucleus to the cytoskeleton, but how N2G performs this activity to maintain nuclear positioning and drive nuclear movement is unclear. This study investigates N2G's role in nucleocytoskeletal coupling, a process critical for cellular function and development. We uncover multiple roles for N2G, including its activity as an F-actin bundler, an adapter that activates kinesin-1 motors, and a mediator of cytoskeletal cross-talk. Notably, N2G directly links kinesin-1 to F-actin, enabling the transport of actin filaments along microtubule tracks, establishing active cross-talk between the actin and microtubule cytoskeletons. These findings provide crucial insights into nuclear movement, advancing our understanding of fundamental cellular processes and their implications in development and disease.
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Affiliation(s)
- Natalie Sahabandu
- Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Kyoko Okada
- Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Aisha Khan
- Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Daniel Elnatan
- Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Daniel A. Starr
- Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | | | - Gant Luxton
- Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Richard J. McKenney
- Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
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6
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Sébastien M, Paquette AL, Prowse ENP, Hendricks AG, Brouhard GJ. Doublecortin restricts neuronal branching by regulating tubulin polyglutamylation. Nat Commun 2025; 16:1749. [PMID: 39966472 PMCID: PMC11836384 DOI: 10.1038/s41467-025-56951-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2024] [Accepted: 02/06/2025] [Indexed: 02/20/2025] Open
Abstract
Doublecortin is a neuronal microtubule-associated protein that regulates microtubule structure in neurons. Mutations in Doublecortin cause lissencephaly and subcortical band heterotopia by impairing neuronal migration. We use CRISPR/Cas9 to knock-out the Doublecortin gene in induced pluripotent stem cells and differentiate the cells into cortical neurons. DCX-KO neurons show reduced velocities of nuclear movements and an increased number of neurites early in neuronal development, consistent with previous findings. Neurite branching is regulated by a host of microtubule-associated proteins, as well as by microtubule polymerization dynamics. However, EB comet dynamics are unchanged in DCX-KO neurons. Rather, we observe a significant reduction in α-tubulin polyglutamylation in DCX-KO neurons. Polyglutamylation levels and neuronal branching are rescued by expression of Doublecortin or of TTLL11, an α-tubulin glutamylase. Using U2OS cells as an orthogonal model system, we show that DCX and TTLL11 act synergistically to promote polyglutamylation. We propose that Doublecortin acts as a positive regulator of α-tubulin polyglutamylation and restricts neurite branching. Our results indicate an unexpected role for Doublecortin in the homeostasis of the tubulin code.
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Affiliation(s)
- Muriel Sébastien
- Department of Biology, McGill University, Montréal, QC, Canada
- Department of Bioengineering, McGill University, Montréal, QC, Canada
| | | | - Emily N P Prowse
- Department of Bioengineering, McGill University, Montréal, QC, Canada
| | - Adam G Hendricks
- Department of Bioengineering, McGill University, Montréal, QC, Canada
| | - Gary J Brouhard
- Department of Biology, McGill University, Montréal, QC, Canada.
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7
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Yildiz A. Mechanism and regulation of kinesin motors. Nat Rev Mol Cell Biol 2025; 26:86-103. [PMID: 39394463 DOI: 10.1038/s41580-024-00780-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/04/2024] [Indexed: 10/13/2024]
Abstract
Kinesins are a diverse superfamily of microtubule-based motors that perform fundamental roles in intracellular transport, cytoskeletal dynamics and cell division. These motors share a characteristic motor domain that powers unidirectional motility and force generation along microtubules, and they possess unique tail domains that recruit accessory proteins and facilitate oligomerization, regulation and cargo recognition. The location, direction and timing of kinesin-driven processes are tightly regulated by various cofactors, adaptors, microtubule tracks and microtubule-associated proteins. This Review focuses on recent structural and functional studies that reveal how members of the kinesin superfamily use the energy of ATP hydrolysis to transport cargoes, depolymerize microtubules and regulate microtubule dynamics. I also survey how accessory proteins and post-translational modifications regulate the autoinhibition, cargo binding and motility of some of the best-studied kinesins. Despite much progress, the mechanism and regulation of kinesins are still emerging, and unresolved questions can now be tackled using newly developed approaches in biophysics and structural biology.
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Affiliation(s)
- Ahmet Yildiz
- Physics Department, University of California at Berkeley, Berkeley, CA, USA.
- Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA, USA.
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8
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Fan X, Okada K, Lin H, Ori-McKenney KM, McKenney RJ. A pathological phosphorylation pattern enhances tau cooperativity on microtubules and facilitates tau filament assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2025:2025.01.29.635117. [PMID: 39974960 PMCID: PMC11838361 DOI: 10.1101/2025.01.29.635117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2025]
Abstract
Phosphorylation plays a crucial role in both normal and disease processes involving the microtubule-associated protein tau. Physiologically, phosphorylation regulates tau's subcellular localization within neurons and is involved in fetal development and animal hibernation. However, abnormal phosphorylation of tau is linked to the formation of neurofibrillary tangles (NFTs) in various human tauopathies. Interestingly, the patterns of tau phosphorylation are similar in both normal and abnormal processes, leaving unclear whether phosphorylated tau retains its functional role in normal processes. The relationship between tau phosphorylation and NFT assembly in tauopathies is also still debated. To address these questions, we investigated the effects of tau phosphorylation on microtubule binding, cooperative protein envelope formation, and NFT filament assembly relevant to tauopathies. Consistent with previous results, our findings show that tau phosphorylation decreases tau's overall affinity for microtubules, but we reveal that phosphorylation more dramatically impacts the cooperativity between tau molecules during tau envelope formation along microtubules. Additionally, we observed that the specific pattern of phosphorylation, rather than overall phosphorylation level, strongly impacts the assembly of tau filaments in vitro . Our results reveal new insights into how tau phosphorylation impacts tau's physiological roles on microtubules and its pathoconversion into NFTs.
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9
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Song D, Song CW, Cho SH, Kwon TY, Jung H, Park KH, Kim J, Seo J, Yoo J, Kim M, Lee GR, Hwang J, Lee HM, Shin J, Shin JH, Jung YS, Chang J. Highly Tunable, Nanomaterial-Functionalized Structural Templating of Intracellular Protein Structures Within Biological Species. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2025; 12:e2406492. [PMID: 39535386 PMCID: PMC11727137 DOI: 10.1002/advs.202406492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 10/15/2024] [Indexed: 11/16/2024]
Abstract
Inside living organisms, proteins are self-assembled into diverse 3D structures optimized for specific functions. This structure-function relationship can be exploited to synthesize functional materials through biotemplating and depositing functional materials onto protein structures. However, conventional biotemplating faces limitations due to the predominantly intracellular existence of proteins and associated challenges in achieving tunability while preserving functionality. In this study, Conversion to Advanced Materials via labeled Biostructures (CamBio), an integrated biotemplating platform that involves labeling target protein structures with antibodies followed by the growth of functional materials, ensuring outstanding nanostructure tunability is proposed. Protein-derived plasmonic nanostructures created by CamBio can serve as precise quantitative tools for assessing target species is demonstrated. The assessment is achieved through highly tunable and efficient surface-enhanced Raman spectroscopy (SERS). CamBio enables the formation of dense nanogap hot spots among metal nanoparticles, templated by diverse fibrous proteins comprising densely repeated monomers. Furthermore, iterative antibody labeling strategies to adjust the antibody density surrounding targets, amplifying the number of nanogaps and consequently improving SERS performance are employed. Finally, cell-patterned substrates and whole meat sections as SERS substrates, confirming their easily accessible, cost-effective, scalable preparation capabilities and dimensional tunability are incorporated.
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Affiliation(s)
- Dae‐Hyeon Song
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Chang Woo Song
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Seunghee H. Cho
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Tae Yoon Kwon
- Department of Mechanical EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Hoeyun Jung
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Ki Hyun Park
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Jiyun Kim
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Junyoung Seo
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Jaeyoung Yoo
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Minjoon Kim
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Gyu Rac Lee
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Jisung Hwang
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Hyuck Mo Lee
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Jonghwa Shin
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Jennifer H. Shin
- Department of Mechanical EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Yeon Sik Jung
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
| | - Jae‐Byum Chang
- Department of Materials Science and EngineeringKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
- Department of Biological SciencesKorea Advanced Institute of Science and TechnologyDaejeon34141South Korea
- Bioimaging Data Curation CenterSeoul03760South Korea
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10
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Wang L, Bu T, Wu X, Gao S, Yun D, Mao B, Li H, Silvestrini B, Li L, Sun F, Cheng CY. Microtubule-Associated Proteins (MAPs) Are Multifunctional Cytoskeletal Proteins in the Testis That Regulate Spermatogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2025; 1469:411-431. [PMID: 40301267 DOI: 10.1007/978-3-031-82990-1_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2025]
Abstract
Microtubule-associated proteins (MAPs) refer to a large superfamily of proteins that bind to microtubules (MTs) structurally, modulating the rapid transition of MTs from a stable state (polymerized) to shrinkage (or catastrophe) via depolymerization through a meta-stable state. Changes of MTs from an assembled structure as linear protofilaments that are a packed/bundled ultrastructure to disassembled subunits of heterodimers of α-/ß-tubulins (or oligomers) can take place in milliseconds within a living cell. These heterodimers can also be rapidly phosphorylated, becoming GTP-bound, or rapidly polymerized into linear protofilaments of MT again. It is such rapid cyclic changes of MTs that support cellular development, growth, and changes in cell shape in response to changes in development or other physiological phenomena, such as the series of cellular events during spermatogenesis, cell divisions, and in response to environmental toxicants to protect cellular life. In this review, we seek to give a concise update and discussion on MAPs. Particularly, we focus on a specific member of the structural MAPs, namely MAP1a, and its interaction with the microtubule affinity regulatory kinases (MARKs, including MARK1, 2, 3, and 4, all are Ser/Thr protein kinases) in particular MARK4, and how these two MAPs work together to regulate MT dynamics in Sertoli cells to support germ cell development. This information should be helpful to investigators who seek to better understand the role of MAPs in testis biology.
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Affiliation(s)
- Lingling Wang
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Tiao Bu
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, Jiangsu, China
- Department of AnesthesiologyAffiliated Hospital of Guangdong Medical University Zhanjiang City, Guangdong Province, China
| | - Xiaolong Wu
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Sheng Gao
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Damin Yun
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, Jiangsu, China
| | - Baiping Mao
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Huitao Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | | | - Linxi Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fei Sun
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - C Yan Cheng
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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11
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Duan D, Koleske AJ. Phase separation of microtubule-binding proteins - implications for neuronal function and disease. J Cell Sci 2024; 137:jcs263470. [PMID: 39679446 PMCID: PMC11795294 DOI: 10.1242/jcs.263470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2024] Open
Abstract
Protein liquid-liquid phase separation (LLPS) is driven by intrinsically disordered regions and multivalent binding domains, both of which are common features of diverse microtubule (MT) regulators. Many in vitro studies have dissected the mechanisms by which MT-binding proteins (MBPs) regulate MT nucleation, stabilization and dynamics, and investigated whether LLPS plays a role in these processes. However, more recent in vivo studies have focused on how MBP LLPS affects biological functions throughout neuronal development. Dysregulation of MBP LLPS can lead to formation of aggregates - an underlying feature in many neurodegenerative diseases - such as the tau neurofibrillary tangles present in Alzheimer's disease. In this Review, we highlight progress towards understanding the regulation of MT dynamics through the lens of phase separation of MBPs and associated cytoskeletal regulators, from both in vitro and in vivo studies. We also discuss how LLPS of MBPs regulates neuronal development and maintains homeostasis in mature neurons.
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Affiliation(s)
- Daisy Duan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Anthony J. Koleske
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
- Department of Neuroscience, Yale University, New Haven, CT 06510, USA
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12
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Jongsma MLM, Bakker N, Voortman LM, Koning RI, Bos E, Akkermans JJLL, Janssen L, Neefjes J. Systems mapping of bidirectional endosomal transport through the crowded cell. Curr Biol 2024; 34:4476-4494.e11. [PMID: 39276769 PMCID: PMC11466077 DOI: 10.1016/j.cub.2024.08.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 07/02/2024] [Accepted: 08/15/2024] [Indexed: 09/17/2024]
Abstract
Kinesin and dynein-dynactin motors move endosomes and other vesicles bidirectionally along microtubules, a process mainly studied under in vitro conditions. Here, we provide a physiological bidirectional transport model following color-coded, endogenously tagged transport-related proteins as they move through a crowded cellular environment. Late endosomes (LEs) surf bidirectionally on Protrudin-enriched endoplasmic reticulum (ER) membrane contact sites, while hopping and gliding along microtubules and bypassing cellular obstacles, such as mitochondria. During bidirectional transport, late endosomes do not switch between opposing Rab7 GTPase effectors, RILP and FYCO1, or their associated dynein and KIF5B motor proteins, respectively. In the endogenous setting, far fewer motors associate with endosomal membranes relative to effectors, implying coordination of transport with other aspects of endosome physiology through GTPase-regulated mechanisms. We find that directionality of transport is provided in part by various microtubule-associated proteins (MAPs), including MID1, EB1, and CEP169, which recruit Lis1-activated dynein motors to microtubule plus ends for transport of early and late endosomal populations. At these microtubule plus ends, activated dynein motors encounter the dynactin subunit p150glued and become competent for endosomal capture and minus-end movement in collaboration with membrane-associated Rab7-RILP. We show that endosomes surf over the ER through the crowded cell and move bidirectionally under the control of MAPs for motor activation and through motor replacement and capture by endosomal anchors.
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Affiliation(s)
- Marlieke L M Jongsma
- Department of Cell and Chemical Biology, ONCODE institute, Leiden University Medical Center LUMC, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
| | - Nina Bakker
- Department of Cell and Chemical Biology, ONCODE institute, Leiden University Medical Center LUMC, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Lenard M Voortman
- Department of Cell and Chemical Biology, ONCODE institute, Leiden University Medical Center LUMC, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Roman I Koning
- Electron Microscopy Facility, Department of Cell and Chemical Biology, Leiden University Medical Centre, P.O. Box 9600, 2300 RC Leiden, the Netherlands
| | - Erik Bos
- Electron Microscopy Facility, Department of Cell and Chemical Biology, Leiden University Medical Centre, P.O. Box 9600, 2300 RC Leiden, the Netherlands
| | - Jimmy J L L Akkermans
- Department of Cell and Chemical Biology, ONCODE institute, Leiden University Medical Center LUMC, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Lennert Janssen
- Department of Cell and Chemical Biology, ONCODE institute, Leiden University Medical Center LUMC, Einthovenweg 20, 2333 ZC Leiden, the Netherlands
| | - Jacques Neefjes
- Department of Cell and Chemical Biology, ONCODE institute, Leiden University Medical Center LUMC, Einthovenweg 20, 2333 ZC Leiden, the Netherlands.
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13
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Sun X, Yu W, Baas PW, Toyooka K, Qiang L. Antagonistic roles of tau and MAP6 in regulating neuronal development. J Cell Sci 2024; 137:jcs261966. [PMID: 39257379 PMCID: PMC11491807 DOI: 10.1242/jcs.261966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 08/20/2024] [Indexed: 09/12/2024] Open
Abstract
Association of tau (encoded by Mapt) with microtubules causes them to be labile, whereas association of MAP6 with microtubules causes them to be stable. As axons differentiate and grow, tau and MAP6 segregate from one another on individual microtubules, resulting in the formation of stable and labile domains. The functional significance of the yin-yang relationship between tau and MAP6 remains speculative, with one idea being that such a relationship assists in balancing morphological stability with plasticity. Here, using primary rodent neuronal cultures, we show that tau depletion has opposite effects compared to MAP6 depletion on the rate of neuronal development, the efficiency of growth cone turning, and the number of neuronal processes and axonal branches. Opposite effects to those seen with tau depletion were also observed on the rate of neuronal migration, in an in vivo assay, when MAP6 was depleted. When tau and MAP6 were depleted together from neuronal cultures, the morphological phenotypes negated one another. Although tau and MAP6 are multifunctional proteins, our results suggest that the observed effects on neuronal development are likely due to their opposite roles in regulating microtubule stability.
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Affiliation(s)
- Xiaohuan Sun
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Wenqian Yu
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Peter W. Baas
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Kazuhito Toyooka
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
| | - Liang Qiang
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
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14
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Tan TC, Shen Y, Stine LB, Mitchell B, Okada K, McKenney RJ, Ori-McKenney KM. Microtubule-associated protein, MAP1B, encodes functionally distinct polypeptides. J Biol Chem 2024; 300:107792. [PMID: 39305956 PMCID: PMC11530598 DOI: 10.1016/j.jbc.2024.107792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2024] [Revised: 09/05/2024] [Accepted: 09/10/2024] [Indexed: 10/18/2024] Open
Abstract
Microtubule-associated protein, MAP1B, is crucial for neuronal morphogenesis and disruptions in MAP1B function are correlated with neurodevelopmental disorders. MAP1B encodes a single polypeptide that is processed into discrete proteins, a heavy chain (HC) and a light chain (LC); however, it is unclear if these two chains operate individually or as a complex within the cell. In vivo studies have characterized the contribution of MAP1B HC and LC to microtubule and actin-based processes, but their molecular mechanisms of action are unknown. Using in vitro reconstitution with purified proteins, we dissect the biophysical properties of the HC and LC and uncover distinct binding behaviors and functional roles for these MAPs. Our biochemical assays indicate that MAP1B HC and LC do not form a constitutive complex, supporting the hypothesis that these proteins operate independently within cells. Both HC and LC inhibit the microtubule motors, kinesin-3, kinesin-4, and dynein, and differentially affect the severing activity of spastin. Notably, MAP1B LC binds to actin filaments in vitro and can simultaneously bind and cross-link actin filaments and microtubules, a function not observed for MAP1B HC. Phosphorylation of MAP1B HC by dual-specificity, tyrosine phosphorylation-regulated kinase 1a negatively regulates its actin-binding activity without significantly affecting its microtubule-binding capacity, suggesting a dynamic contribution of MAP1B HC in cytoskeletal organization. Overall, our study provides new insights into the distinct functional properties of MAP1B HC and LC, underscoring their roles in coordinating cytoskeletal networks during neuronal development.
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Affiliation(s)
- Tracy C Tan
- Department of Molecular and Cellular Biology, University of California, Davis, California, USA
| | - Yusheng Shen
- Department of Molecular and Cellular Biology, University of California, Davis, California, USA
| | - Lily B Stine
- Department of Molecular and Cellular Biology, University of California, Davis, California, USA
| | - Barbara Mitchell
- Department of Molecular and Cellular Biology, University of California, Davis, California, USA
| | - Kyoko Okada
- Department of Molecular and Cellular Biology, University of California, Davis, California, USA
| | - Richard J McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, California, USA.
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15
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Seo D, Yue Y, Yamazaki S, Verhey KJ, Gammon DB. Poxvirus A51R Proteins Negatively Regulate Microtubule-Dependent Transport by Kinesin-1. Int J Mol Sci 2024; 25:7825. [PMID: 39063067 PMCID: PMC11277487 DOI: 10.3390/ijms25147825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 07/09/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
Microtubule (MT)-dependent transport is a critical means of intracellular movement of cellular cargo by kinesin and dynein motors. MT-dependent transport is tightly regulated by cellular MT-associated proteins (MAPs) that directly bind to MTs and either promote or impede motor protein function. Viruses have been widely shown to usurp MT-dependent transport to facilitate their virion movement to sites of replication and/or for exit from the cell. However, it is unclear if viruses also negatively regulate MT-dependent transport. Using single-molecule motility and cellular transport assays, we show that the vaccinia virus (VV)-encoded MAP, A51R, inhibits kinesin-1-dependent transport along MTs in vitro and in cells. This inhibition is selective as the function of kinesin-3 is largely unaffected by VV A51R. Interestingly, we show that A51R promotes the perinuclear accumulation of cellular cargo transported by kinesin-1 such as lysosomes and mitochondria during infection. Moreover, A51R also regulates the release of specialized VV virions that exit the cell using kinesin-1-dependent movement. Using a fluorescently tagged rigor mutant of kinesin-1, we show that these motors accumulate on A51R-stabilized MTs, suggesting these stabilized MTs may form a "kinesin-1 sink" to regulate MT-dependent transport in the cell. Collectively, our findings uncover a new mechanism by which viruses regulate host cytoskeletal processes.
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Affiliation(s)
- Dahee Seo
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yang Yue
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Shin Yamazaki
- Department of Neuroscience and Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kristen J. Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Don B. Gammon
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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16
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Shen Y, Ori-McKenney KM. Microtubule-associated protein MAP7 promotes tubulin posttranslational modifications and cargo transport to enable osmotic adaptation. Dev Cell 2024; 59:1553-1570.e7. [PMID: 38574732 PMCID: PMC11187767 DOI: 10.1016/j.devcel.2024.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 09/11/2023] [Accepted: 03/12/2024] [Indexed: 04/06/2024]
Abstract
Cells remodel their cytoskeletal networks to adapt to their environment. Here, we analyze the mechanisms utilized by the cell to tailor its microtubule landscape in response to changes in osmolarity that alter macromolecular crowding. By integrating live-cell imaging, ex vivo enzymatic assays, and in vitro reconstitution, we probe the impact of cytoplasmic density on microtubule-associated proteins (MAPs) and tubulin posttranslational modifications (PTMs). We find that human epithelial cells respond to fluctuations in cytoplasmic density by modulating microtubule acetylation, detyrosination, or MAP7 association without differentially affecting polyglutamylation, tyrosination, or MAP4 association. These MAP-PTM combinations alter intracellular cargo transport, enabling the cell to respond to osmotic challenges. We further dissect the molecular mechanisms governing tubulin PTM specification and find that MAP7 promotes acetylation and inhibits detyrosination. Our data identify MAP7 in modulating the tubulin code, resulting in microtubule cytoskeleton remodeling and alteration of intracellular transport as an integrated mechanism of cellular adaptation.
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Affiliation(s)
- Yusheng Shen
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Kassandra M Ori-McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA.
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17
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Xiong GJ, Sheng ZH. Presynaptic perspective: Axonal transport defects in neurodevelopmental disorders. J Cell Biol 2024; 223:e202401145. [PMID: 38568173 PMCID: PMC10988239 DOI: 10.1083/jcb.202401145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/05/2024] Open
Abstract
Disruption of synapse assembly and maturation leads to a broad spectrum of neurodevelopmental disorders. Presynaptic proteins are largely synthesized in the soma, where they are packaged into precursor vesicles and transported into distal axons to ensure precise assembly and maintenance of presynapses. Due to their morphological features, neurons face challenges in the delivery of presynaptic cargos to nascent boutons. Thus, targeted axonal transport is vital to build functional synapses. A growing number of mutations in genes encoding the transport machinery have been linked to neurodevelopmental disorders. Emerging lines of evidence have started to uncover presynaptic mechanisms underlying axonal transport defects, thus broadening the view of neurodevelopmental disorders beyond postsynaptic mechanisms. In this review, we discuss presynaptic perspectives of neurodevelopmental disorders by focusing on impaired axonal transport and disturbed assembly and maintenance of presynapses. We also discuss potential strategies for restoring axonal transport as an early therapeutic intervention.
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Affiliation(s)
- Gui-Jing Xiong
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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18
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Beaudet D, Berger CL, Hendricks AG. The types and numbers of kinesins and dyneins transporting endocytic cargoes modulate their motility and response to tau. J Biol Chem 2024; 300:107323. [PMID: 38677516 PMCID: PMC11130734 DOI: 10.1016/j.jbc.2024.107323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 04/29/2024] Open
Abstract
Organelles and vesicular cargoes are transported by teams of kinesin and dynein motors along microtubules. We isolated endocytic organelles from cells at different stages of maturation and reconstituted their motility along microtubules in vitro. We asked how the sets of motors transporting a cargo determine its motility and response to the microtubule-associated protein tau. Here, we find that phagosomes move in both directions along microtubules, but the directional bias changes during maturation. Early phagosomes exhibit retrograde-biased transport while late phagosomes are directionally unbiased. Correspondingly, early and late phagosomes are bound by different numbers and combinations of kinesins-1, -2, -3, and dynein. Tau stabilizes microtubules and directs transport within neurons. While single-molecule studies show that tau differentially regulates the motility of kinesins and dynein in vitro, less is known about its role in modulating the trafficking of endogenous cargoes transported by their native teams of motors. Previous studies showed that tau preferentially inhibits kinesin motors, which biases late phagosome transport towards the microtubule minus-end. Here, we show that tau strongly inhibits long-range, dynein-mediated motility of early phagosomes. Tau reduces forces generated by teams of dynein motors on early phagosomes and accelerates dynein unbinding under load. Thus, cargoes differentially respond to tau, where dynein complexes on early phagosomes are more sensitive to tau inhibition than those on late phagosomes. Mathematical modeling further explains how small changes in the number of kinesins and dynein on cargoes impact the net directionality but also that cargoes with different sets of motors respond differently to tau.
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Affiliation(s)
- Daniel Beaudet
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada
| | - Christopher L Berger
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont, USA
| | - Adam G Hendricks
- Department of Bioengineering, McGill University, Montreal, Quebec, Canada.
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19
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Chen Q, Li S, Fu F, Huang Q, Zhang R. MAP7 drives EMT and cisplatin resistance in ovarian cancer via wnt/β-catenin signaling. Heliyon 2024; 10:e30409. [PMID: 38726137 PMCID: PMC11078642 DOI: 10.1016/j.heliyon.2024.e30409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/12/2024] Open
Abstract
Methods Our approach encompasses analyzing MAP7's expression levels across various datasets and clinical specimens, evaluating its association with patient outcomes, and probing its influence on ovarian cancer cell dynamics such as proliferation, migration, invasion, and apoptosis. Results We have identified significant upregulation of MAP7 in ovarian cancer tissues, which correlates with advanced disease stages, higher pathological grades, and unfavorable prognoses. Functionally, the inhibition of MAP7 suppresses cancer cell proliferation, migration, and invasion while promoting apoptosis. Notably, the silencing of MAP7 attenuates the epithelial-mesenchymal transition (EMT) and disrupts Wnt/β-catenin pathway signaling-two critical processes implicated in metastasis and chemoresistance. In cisplatin-resistant A2780-DDP cells, the downregulation of MAP7 effectively reverses their resistance to cisplatin. Furthermore, the nuclear localization of MAP7 in these cells underscores its pivotal role in driving cisplatin resistance by modulating the transcriptional regulation and interaction dynamics of β-catenin. Conclusion Our findings position MAP7 as a pivotal element in ovarian cancer advancement and cisplatin resistance, primarily through its modulation of EMT and the Wnt/β-catenin pathway. Its association with poor clinical outcomes underscores its potential as both a prognostic marker and a therapeutic target. Strategies aimed at MAP7 could represent a new frontier in combating chemotherapy resistance in ovarian cancer, emphasizing its significance in crafting complementary treatments for this disease.
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Affiliation(s)
- Qingqing Chen
- The Third School of Clinical Medicine,Southern Medical University, Guangzhou, 510500, China
| | - Shaojing Li
- Shanghai Fengxian District Central Hospital, 6600 Nanfeng Road, Fengxian District, Shanghai, 201400, China
| | - Furong Fu
- Pingyang Hospital affiliated to Wenzhou Medical University, No.555, Kunao Road, Zhejiang Province, China
| | - Qunhuan Huang
- Shanghai Fengxian District Central Hospital, 6600 Nanfeng Road, Fengxian District, Shanghai, 201400, China
- Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Rong Zhang
- The Third School of Clinical Medicine,Southern Medical University, Guangzhou, 510500, China
- Shanghai Fengxian District Central Hospital, 6600 Nanfeng Road, Fengxian District, Shanghai, 201400, China
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20
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Montgomery AC, Mendoza CS, Garbouchian A, Quinones GB, Bentley M. Polarized transport requires AP-1-mediated recruitment of KIF13A and KIF13B at the trans-Golgi. Mol Biol Cell 2024; 35:ar61. [PMID: 38446634 PMCID: PMC11151104 DOI: 10.1091/mbc.e23-10-0401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024] Open
Abstract
Neurons are polarized cells that require accurate membrane trafficking to maintain distinct protein complements at dendritic and axonal membranes. The Kinesin-3 family members KIF13A and KIF13B are thought to mediate dendrite-selective transport, but the mechanism by which they are recruited to polarized vesicles and the differences in the specific trafficking role of each KIF13 have not been defined. We performed live-cell imaging in cultured hippocampal neurons and found that KIF13A is a dedicated dendrite-selective kinesin. KIF13B confers two different transport modes, dendrite- and axon-selective transport. Both KIF13s are maintained at the trans-Golgi network by interactions with the heterotetrameric adaptor protein complex AP-1. Interference with KIF13 binding to AP-1 resulted in disruptions to both dendrite- and axon-selective trafficking. We propose that AP-1 is the molecular link between the sorting of polarized cargoes into vesicles and the recruitment of kinesins that confer polarized transport.
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Affiliation(s)
- Andrew C Montgomery
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Christina S Mendoza
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Alex Garbouchian
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Geraldine B Quinones
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Marvin Bentley
- Department of Biological Sciences and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
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21
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Wang L, Yan M, Bu T, Wu X, Li L, Silvestrini B, Sun F, Cheng CY, Chen H. Map-1a regulates Sertoli cell BTB dynamics through the cytoskeletal organization of microtubule and F-actin. Reprod Biol Endocrinol 2024; 22:36. [PMID: 38570783 PMCID: PMC10988971 DOI: 10.1186/s12958-024-01204-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 03/11/2024] [Indexed: 04/05/2024] Open
Abstract
Microtubule-associated protein 1a (Map1a) is a microtubule (MT) regulatory protein that binds to the MT protofilaments in mammalian cells to promote MT stabilization. Maps work with MT cleavage proteins and other MT catastrophe-inducing proteins to confer MT dynamics to support changes in the Sertoli cell shape to sustain spermatogenesis. However, no functional studies are found in the literature to probe its role in spermatogenesis. Using an RNAi approach, coupled with the use of toxicant-induced testis (in vivo)- and Sertoli cell (in vitro)-injury models, RNA-Seq analysis, transcriptome profiling, and relevant bioinformatics analysis, immunofluorescence analysis, and pertinent biochemical assays for cytoskeletal organization, we have delineated the functional role of Map1a in Sertoli cells and testes. Map1a was shown to support MT structural organization, and its knockdown (KD) also perturbed the structural organization of actin, vimentin, and septin cytoskeletons as these cytoskeletons are intimately related, working in concert to support spermatogenesis. More importantly, cadmium-induced Sertoli cell injury that perturbed the MT structural organization across the cell cytoplasm was associated with disruptive changes in the distribution of Map1a and a surge in p-p38-MAPK (phosphorylated p38-mitogen-activated protein kinase) expression but not total p38-MAPK. These findings thus support the notion that p-p38-MAPK activation is involved in cadmium-induced Sertoli cell injury. This conclusion was supported by studies using doramapimod, a specific p38-MAPK phosphorylation (activation) inhibitor, which was capable of restoring the cadmium-induced disruptive structural organization of MTs across the Sertoli cell cytoplasm. In summary: this study provides mechanistic insights regarding restoration of toxicant-induced Sertoli cell and testis injury and male infertility.
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Affiliation(s)
- Lingling Wang
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, Jiangsu, China
| | - Ming Yan
- Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China
| | - Tiao Bu
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, Jiangsu, China
| | - Xiaolong Wu
- Department of Urology and Andrology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, 310016, Zhejiang, China
| | - Linxi Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Zhejiang 325027, Wenzhou, China
| | - Bruno Silvestrini
- Faculty of Pharmacy, University of Rome La Sapienza, P. Le Aldo Moro 5, 00185, Rome, Italy
| | - Fei Sun
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, Jiangsu, China.
| | - C Yan Cheng
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, Jiangsu, China.
| | - Hao Chen
- Institute of Reproductive Medicine, Medical School of Nantong University, Nantong, 226001, Jiangsu, China.
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22
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Andreu-Carbó M, Egoldt C, Velluz MC, Aumeier C. Microtubule damage shapes the acetylation gradient. Nat Commun 2024; 15:2029. [PMID: 38448418 PMCID: PMC10918088 DOI: 10.1038/s41467-024-46379-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/16/2024] [Indexed: 03/08/2024] Open
Abstract
The properties of single microtubules within the microtubule network can be modulated through post-translational modifications (PTMs), including acetylation within the lumen of microtubules. To access the lumen, the enzymes could enter through the microtubule ends and at damage sites along the microtubule shaft. Here we show that the acetylation profile depends on damage sites, which can be caused by the motor protein kinesin-1. Indeed, the entry of the deacetylase HDAC6 into the microtubule lumen can be modulated by kinesin-1-induced damage sites. In contrast, activity of the microtubule acetylase αTAT1 is independent of kinesin-1-caused shaft damage. On a cellular level, our results show that microtubule acetylation distributes in an exponential gradient. This gradient results from tight regulation of microtubule (de)acetylation and scales with the size of the cells. The control of shaft damage represents a mechanism to regulate PTMs inside the microtubule by giving access to the lumen.
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Affiliation(s)
| | - Cornelia Egoldt
- Department of Biochemistry, University of Geneva, 1211, Geneva, Switzerland
| | | | - Charlotte Aumeier
- Department of Biochemistry, University of Geneva, 1211, Geneva, Switzerland.
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23
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Adler A, Bangera M, Beugelink JW, Bahri S, van Ingen H, Moores CA, Baldus M. A structural and dynamic visualization of the interaction between MAP7 and microtubules. Nat Commun 2024; 15:1948. [PMID: 38431715 PMCID: PMC10908866 DOI: 10.1038/s41467-024-46260-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 02/21/2024] [Indexed: 03/05/2024] Open
Abstract
Microtubules (MTs) are key components of the eukaryotic cytoskeleton and are essential for intracellular organization, organelle trafficking and mitosis. MT tasks depend on binding and interactions with MT-associated proteins (MAPs). MT-associated protein 7 (MAP7) has the unusual ability of both MT binding and activating kinesin-1-mediated cargo transport along MTs. Additionally, the protein is reported to stabilize MTs with its 112 amino-acid long MT-binding domain (MTBD). Here we investigate the structural basis of the interaction of MAP7 MTBD with the MT lattice. Using a combination of solid and solution-state nuclear magnetic resonance (NMR) spectroscopy with electron microscopy, fluorescence anisotropy and isothermal titration calorimetry, we shed light on the binding mode of MAP7 to MTs at an atomic level. Our results show that a combination of interactions between MAP7 and MT lattice extending beyond a single tubulin dimer and including tubulin C-terminal tails contribute to formation of the MAP7-MT complex.
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Affiliation(s)
- Agnes Adler
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Mamata Bangera
- Institute of Structural and Molecular Biology, School of Natural Sciences, Birkbeck, University of London, London, WC1E 7HX, UK
| | - J Wouter Beugelink
- Structural Biochemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Salima Bahri
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Hugo van Ingen
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Carolyn A Moores
- Institute of Structural and Molecular Biology, School of Natural Sciences, Birkbeck, University of London, London, WC1E 7HX, UK.
| | - Marc Baldus
- NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
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24
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Chiba K, Niwa S. Autoinhibition and activation of kinesin-1 and their involvement in amyotrophic lateral sclerosis. Curr Opin Cell Biol 2024; 86:102301. [PMID: 38096601 DOI: 10.1016/j.ceb.2023.102301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/11/2023] [Accepted: 11/22/2023] [Indexed: 02/15/2024]
Abstract
Kinesin-1, composed of kinesin heavy chain and kinesin light chain, is a founding member of kinesin superfamily and transports various neuronal cargos. Kinesin-1 is one of the most abundant ATPases in the cell and thus need to be tightly regulated to avoid wastage of energy. It has been well established that kinesin-1 is regulated by the autoinhibition mechanism. This review focuses on the recent researches that have contributed to the understanding of mechanisms for the autoinhibition of kinesin-1 and its unlocking. Recent electron microscopic studies have shown an unanticipated structure of autoinhibited kinesin-1. Biochemical reconstitution have revealed detailed molecular mechanisms how the autoinhibition is unlocked. Importantly, misregulation of kinesin-1 is emerging as one of the major causes of amyotrophic lateral sclerosis.
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Affiliation(s)
- Kyoko Chiba
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan
| | - Shinsuke Niwa
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan; Graduate School of Life Sciences, Tohoku University, 2-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
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25
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Tran MV, Khuntsariya D, Fetter RD, Ferguson JW, Wang JT, Long AF, Cote LE, Wellard SR, Vázquez-Martínez N, Sallee MD, Genova M, Magiera MM, Eskinazi S, Lee JD, Peel N, Janke C, Stearns T, Shen K, Lansky Z, Magescas J, Feldman JL. MAP9/MAPH-9 supports axonemal microtubule doublets and modulates motor movement. Dev Cell 2024; 59:199-210.e11. [PMID: 38159567 PMCID: PMC11385174 DOI: 10.1016/j.devcel.2023.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 08/15/2023] [Accepted: 12/04/2023] [Indexed: 01/03/2024]
Abstract
Microtubule doublets (MTDs) comprise an incomplete microtubule (B-tubule) attached to the side of a complete cylindrical microtubule. These compound microtubules are conserved in cilia across the tree of life; however, the mechanisms by which MTDs form and are maintained in vivo remain poorly understood. Here, we identify microtubule-associated protein 9 (MAP9) as an MTD-associated protein. We demonstrate that C. elegans MAPH-9, a MAP9 homolog, is present during MTD assembly and localizes exclusively to MTDs, a preference that is in part mediated by tubulin polyglutamylation. We find that loss of MAPH-9 causes ultrastructural MTD defects, including shortened and/or squashed B-tubules with reduced numbers of protofilaments, dysregulated axonemal motor velocity, and perturbed cilia function. Because we find that the mammalian ortholog MAP9 localizes to axonemes in cultured mammalian cells and mouse tissues, we propose that MAP9/MAPH-9 plays a conserved role in regulating ciliary motors and supporting the structure of axonemal MTDs.
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Affiliation(s)
- Michael V Tran
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Daria Khuntsariya
- Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, 25250 Vestec, Prague West, Czech Republic
| | - Richard D Fetter
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - James W Ferguson
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Jennifer T Wang
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Alexandra F Long
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Lauren E Cote
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | | | - Maria D Sallee
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Mariya Genova
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France; Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Maria M Magiera
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France; Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Sani Eskinazi
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | | | - Nina Peel
- The College of New Jersey, Ewing, NJ 08628, USA
| | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348, Orsay, France; Université Paris-Saclay, CNRS UMR3348, Orsay, France
| | - Tim Stearns
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Zdenek Lansky
- Institute of Biotechnology, Czech Academy of Sciences, BIOCEV, 25250 Vestec, Prague West, Czech Republic
| | - Jérémy Magescas
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
| | - Jessica L Feldman
- Department of Biology, Stanford University, Stanford, CA 94305, USA.
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26
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Ori-McKenney KM, McKenney RJ. Tau oligomerization on microtubules in health and disease. Cytoskeleton (Hoboken) 2024; 81:35-40. [PMID: 37747123 PMCID: PMC10841430 DOI: 10.1002/cm.21785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/26/2023]
Affiliation(s)
- Kassandra M Ori-McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
| | - Richard J McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, California, USA
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27
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Volkov VA, Akhmanova A. Phase separation on microtubules: from droplet formation to cellular function? Trends Cell Biol 2024; 34:18-30. [PMID: 37453878 DOI: 10.1016/j.tcb.2023.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 06/18/2023] [Accepted: 06/19/2023] [Indexed: 07/18/2023]
Abstract
Microtubules are cytoskeletal polymers that play important roles in numerous cellular processes, ranging from the control of cell shape and polarity to cell division and intracellular transport. Many of these roles rely on proteins that bind to microtubule ends and shafts, carry intrinsically disordered regions, and form complex multivalent interaction networks. A flurry of recent studies demonstrated that these properties allow diverse microtubule-binding proteins to undergo liquid-liquid phase separation (LLPS) in vitro. It is proposed that LLPS could potentially affect multiple microtubule-related processes, such as microtubule nucleation, control of microtubule dynamics and organization, and microtubule-based transport. Here, we discuss the evidence in favor and against the occurrence of LLPS and its functional significance for microtubule-based processes in cells.
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Affiliation(s)
- Vladimir A Volkov
- School of Biological and Behavioural Sciences, Queen Mary University of London, London, E1 4NS, UK.
| | - Anna Akhmanova
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands.
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28
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Selvarasu K, Singh AK, Dakshinamoorthy A, Sreenivasmurthy SG, Iyaswamy A, Radhakrishnan M, Patnaik S, Huang JD, Williams LL, Senapati S, Durairajan SSK. Interaction of Tau with Kinesin-1: Effect of Kinesin-1 Heavy Chain Elimination on Autophagy-Mediated Mutant Tau Degradation. Biomedicines 2023; 12:5. [PMID: 38275365 PMCID: PMC10813313 DOI: 10.3390/biomedicines12010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/08/2023] [Accepted: 12/14/2023] [Indexed: 01/27/2024] Open
Abstract
Natively unfolded tau has a low propensity to form aggregates, but in tauopathies, such as Alzheimer's disease (AD), tau aggregates into paired helical filaments (PHFs) and neurofibrillary tangles (NFTs). Multiple intracellular transport pathways utilize kinesin-1, a plus-end-directed microtubule-based motor. Kinesin-1 is crucial in various neurodegenerative diseases as it transports multiple cargoes along the microtubules (MT). Kinesin-1 proteins cannot progress along MTs due to an accumulation of tau on their surfaces. Although kinesin-1-mediated neuronal transport dysfunction is well-documented in other neurodegenerative diseases, its role in AD has received less attention. Very recently, we have shown that knocking down and knocking out of kinesin-1 heavy chain (KIF5B KO) expression significantly reduced the level and stability of tau in cells and tau transgenic mice, respectively. Here, we report that tau interacts with the motor domain of KIF5B in vivo and in vitro, possibly through its microtubule-binding repeat domain. This interaction leads to the inhibition of the ATPase activity of the motor domain. In addition, the KIF5B KO results in autophagy initiation, which subsequently assists in tau degradation. The mechanisms behind KIF5B KO-mediated tau degradation seem to involve its interaction with tau, promoting the trafficking of tau through retrograde transport into autophagosomes for subsequent lysosomal degradation of tau. Our results suggest how KIF5B removal facilitates the movement of autophagosomes toward lysosomes for efficient tau degradation. This mechanism can be enabled through the downregulation of kinesin-1 or the disruption of the association between kinesin-1 and tau, particularly in cases when neurons perceive disturbances in intercellular axonal transport.
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Affiliation(s)
- Karthikeyan Selvarasu
- Molecular Mycology and Neurodegenerative Disease Research Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur 610 005, India; (K.S.); (A.K.S.); (S.P.)
| | - Abhay Kumar Singh
- Molecular Mycology and Neurodegenerative Disease Research Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur 610 005, India; (K.S.); (A.K.S.); (S.P.)
| | - Avinash Dakshinamoorthy
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India; (A.D.); (S.S.)
| | | | - Ashok Iyaswamy
- Mr. & Mrs. Ko Chi-Ming Centre for Parkinson’s Disease Research, School of Chinese Medicine, Hong Kong Baptist University, Hong Kong SAR, China;
- Department of Biochemistry, Karpagam Academy of Higher Education, Coimbatore 641021, India
| | - Moorthi Radhakrishnan
- Molecular Mycology and Neurodegenerative Disease Research Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur 610 005, India; (K.S.); (A.K.S.); (S.P.)
| | - Supriti Patnaik
- Molecular Mycology and Neurodegenerative Disease Research Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur 610 005, India; (K.S.); (A.K.S.); (S.P.)
| | - Jian-Dong Huang
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Leonard L. Williams
- Center for Excellence in Post Harvest Technologies, North Carolina Agricultural and Technical State University, The North Carolina Research Campus, 500 Laureate Way, Kannapolis, NC 28081, USA
| | - Sanjib Senapati
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India; (A.D.); (S.S.)
| | - Siva Sundara Kumar Durairajan
- Molecular Mycology and Neurodegenerative Disease Research Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur 610 005, India; (K.S.); (A.K.S.); (S.P.)
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
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29
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Lawrence EJ, Chatterjee S, Zanic M. More is different: Reconstituting complexity in microtubule regulation. J Biol Chem 2023; 299:105398. [PMID: 37898404 PMCID: PMC10694663 DOI: 10.1016/j.jbc.2023.105398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/13/2023] [Accepted: 10/18/2023] [Indexed: 10/30/2023] Open
Abstract
Microtubules are dynamic cytoskeletal filaments that undergo stochastic switching between phases of polymerization and depolymerization-a behavior known as dynamic instability. Many important cellular processes, including cell motility, chromosome segregation, and intracellular transport, require complex spatiotemporal regulation of microtubule dynamics. This coordinated regulation is achieved through the interactions of numerous microtubule-associated proteins (MAPs) with microtubule ends and lattices. Here, we review the recent advances in our understanding of microtubule regulation, focusing on results arising from biochemical in vitro reconstitution approaches using purified multiprotein ensembles. We discuss how the combinatory effects of MAPs affect both the dynamics of individual microtubule ends, as well as the stability and turnover of the microtubule lattice. In addition, we highlight new results demonstrating the roles of protein condensates in microtubule regulation. Our overall intent is to showcase how lessons learned from reconstitution approaches help unravel the regulatory mechanisms at play in complex cellular environments.
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Affiliation(s)
- Elizabeth J Lawrence
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Saptarshi Chatterjee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA
| | - Marija Zanic
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, USA; Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee, USA; Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA.
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30
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D'Souza AI, Grover R, Monzon GA, Santen L, Diez S. Vesicles driven by dynein and kinesin exhibit directional reversals without regulators. Nat Commun 2023; 14:7532. [PMID: 37985763 PMCID: PMC10662051 DOI: 10.1038/s41467-023-42605-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 10/16/2023] [Indexed: 11/22/2023] Open
Abstract
Intracellular vesicular transport along cytoskeletal filaments ensures targeted cargo delivery. Such transport is rarely unidirectional but rather bidirectional, with frequent directional reversals owing to the simultaneous presence of opposite-polarity motors. So far, it has been unclear whether such complex motility pattern results from the sole mechanical interplay between opposite-polarity motors or requires regulators. Here, we demonstrate that a minimal system, comprising purified Dynein-Dynactin-BICD2 (DDB) and kinesin-3 (KIF16B) attached to large unilamellar vesicles, faithfully reproduces in vivo cargo motility, including runs, pauses, and reversals. Remarkably, opposing motors do not affect vesicle velocity during runs. Our computational model reveals that the engagement of a small number of motors is pivotal for transitioning between runs and pauses. Taken together, our results suggest that motors bound to vesicular cargo transiently engage in a tug-of-war during pauses. Subsequently, stochastic motor attachment and detachment events can lead to directional reversals without the need for regulators.
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Affiliation(s)
- Ashwin I D'Souza
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Dresden, Germany
| | - Rahul Grover
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Dresden, Germany
| | - Gina A Monzon
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Dresden, Germany
- Center for Biophysics, Department of Physics, Saarland University, Saarbrücken, Germany
| | - Ludger Santen
- Center for Biophysics, Department of Physics, Saarland University, Saarbrücken, Germany.
| | - Stefan Diez
- B CUBE - Center for Molecular Bioengineering, TU Dresden, Dresden, Germany.
- Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany.
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
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31
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Hoshino A, Clemente V, Shetty M, Castle B, Odde D, Bazzaro M. The microtubule-severing protein UNC-45A preferentially binds to curved microtubules and counteracts the microtubule-straightening effects of Taxol. J Biol Chem 2023; 299:105355. [PMID: 37858676 PMCID: PMC10654038 DOI: 10.1016/j.jbc.2023.105355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 09/28/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023] Open
Abstract
Uncoordinated protein 45A (UNC-45A) is the only known ATP-independent microtubule (MT)-severing protein. Thus, it severs MTs via a novel mechanism. In vitro and in cells, UNC-45A-mediated MT severing is preceded by the appearance of MT bends. While MTs are stiff biological polymers, in cells, they often curve, and the result of this curving can be breaking off. The contribution of MT-severing proteins on MT lattice curvature is largely undefined. Here, we show that UNC-45A curves MTs. Using in vitro biophysical reconstitution and total internal fluorescence microscopy analysis, we show that UNC-45A is enriched in the areas where MTs are curved versus the areas where MTs are straight. In cells, we show that UNC-45A overexpression increases MT curvature and its depletion has the opposite effect. We also show that this effect occurs is independent of actomyosin contractility. Lastly, we show for the first time that in cells, Paclitaxel straightens MTs, and that UNC-45A can counteracts the MT-straightening effects of the drug.
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Affiliation(s)
- Asumi Hoshino
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Valentino Clemente
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Mihir Shetty
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Health, University of Minnesota, Minneapolis, Minnesota, USA
| | - Brian Castle
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - David Odde
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota, USA
| | - Martina Bazzaro
- Masonic Cancer Center and Department of Obstetrics, Gynecology and Women's Health, University of Minnesota, Minneapolis, Minnesota, USA.
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32
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Tan Z, Yue Y, Leprevost F, Haynes S, Basrur V, Nesvizhskii AI, Verhey KJ, Cianfrocco MA. Autoinhibited kinesin-1 adopts a hierarchical folding pattern. eLife 2023; 12:RP86776. [PMID: 37910016 PMCID: PMC10619981 DOI: 10.7554/elife.86776] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Conventional kinesin-1 is the primary anterograde motor in cells for transporting cellular cargo. While there is a consensus that the C-terminal tail of kinesin-1 inhibits motility, the molecular architecture of a full-length autoinhibited kinesin-1 remains unknown. Here, we combine crosslinking mass spectrometry (XL-MS), electron microscopy (EM), and AlphaFold structure prediction to determine the architecture of the full-length autoinhibited kinesin-1 homodimer (kinesin-1 heavy chain [KHC]) and kinesin-1 heterotetramer (KHC bound to kinesin light chain 1 [KLC1]). Our integrative analysis shows that kinesin-1 forms a compact, bent conformation through a break in coiled-coil 3. Moreover, our XL-MS analysis demonstrates that kinesin light chains stabilize the folded inhibited state rather than inducing a new structural state. Using our structural model, we show that disruption of multiple interactions between the motor, stalk, and tail domains is required to activate the full-length kinesin-1. Our work offers a conceptual framework for understanding how cargo adaptors and microtubule-associated proteins relieve autoinhibition to promote activation.
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Affiliation(s)
- Zhenyu Tan
- Department of Biophysics, University of MichiganAnn ArborUnited States
- Life Sciences Institute, University of MichiganAnn ArborUnited States
| | - Yang Yue
- Department of Cell & Developmental Biology, University of MichiganAnn ArborUnited States
| | - Felipe Leprevost
- Department of Pathology, University of MichiganAnn ArborUnited States
| | - Sarah Haynes
- Department of Pathology, University of MichiganAnn ArborUnited States
| | - Venkatesha Basrur
- Department of Pathology, University of MichiganAnn ArborUnited States
| | - Alexey I Nesvizhskii
- Department of Pathology, University of MichiganAnn ArborUnited States
- Department of Computational Medicine and Bioinformatics, University of MichiganAnn ArborUnited States
| | - Kristen J Verhey
- Department of Cell & Developmental Biology, University of MichiganAnn ArborUnited States
| | - Michael A Cianfrocco
- Life Sciences Institute, University of MichiganAnn ArborUnited States
- Department of Biological Chemistry, University of MichiganAnn ArborUnited States
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33
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Tan Z, Yue Y, da Veiga Leprevost F, Haynes SE, Basrur V, Nesvizhskii AI, Verhey KJ, Cianfrocco MA. Autoinhibited kinesin-1 adopts a hierarchical folding pattern. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.26.525761. [PMID: 36747757 PMCID: PMC9901034 DOI: 10.1101/2023.01.26.525761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Conventional kinesin-1 is the primary anterograde motor in cells for transporting cellular cargo. While there is a consensus that the C-terminal tail of kinesin-1 inhibits motility, the molecular architecture of a full-length autoinhibited kinesin-1 remains unknown. Here, we combine cross-linking mass spectrometry (XL-MS), electron microscopy (EM), and AlphaFold structure prediction to determine the architecture of the full-length autoinhibited kinesin-1 homodimer [kinesin-1 heavy chain (KHC)] and kinesin-1 heterotetramer [KHC bound to kinesin light chain 1 (KLC1)]. Our integrative analysis shows that kinesin-1 forms a compact, bent conformation through a break in coiled coil 3. Moreover, our XL-MS analysis demonstrates that kinesin light chains stabilize the folded inhibited state rather than inducing a new structural state. Using our structural model, we show that disruption of multiple interactions between the motor, stalk, and tail domains is required to activate the full-length kinesin-1. Our work offers a conceptual framework for understanding how cargo adaptors and microtubule-associated proteins relieve autoinhibition to promote activation.
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Affiliation(s)
- Zhenyu Tan
- Department of Biophysics, University of Michigan
- Life Sciences Institute, University of Michigan
| | - Yang Yue
- Department of Cell & Developmental Biology, University of Michigan
| | | | | | | | - Alexey I. Nesvizhskii
- Department of Pathology, University of Michigan
- Department of Computational Medicine and Bioinformatics, University of Michigan
| | | | - Michael A. Cianfrocco
- Life Sciences Institute, University of Michigan
- Department of Biological Chemistry, University of Michigan
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34
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Hoshino A, Clemente V, Shetty M, Castle B, Odde D, Bazzaro M. The Microtubule Severing Protein UNC-45A Counteracts the Microtubule Straightening Effects of Taxol. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.12.557417. [PMID: 37745537 PMCID: PMC10515786 DOI: 10.1101/2023.09.12.557417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
UNC-45A is the only known ATP-independent microtubule (MT) severing protein. Thus, it severs MTs via a novel mechanism. In vitro and in cells UNC-45A-mediated MT severing is preceded by the appearance of MT bends. While MTs are stiff biological polymers, in cells, they often curve, and the result of this curving can be breaking off. The contribution of MT severing proteins on MT lattice curvature is largely undefined. Here we show that UNC-45A curves MTs. Using in vitro biophysical reconstitution and TIRF microscopy analysis, we show that UNC-45A is enriched in the areas where MTs are curved versus the areas where MTs are straight. In cells, we show that UNC-45A overexpression increases MT curvature and its depletion has the opposite effect. We also show that this effect occurs is independent of actomyosin contractility. Lastly, we show for the first time that in cells, Paclitaxel straightens MTs, and that UNC-45A can counteracts the MT straightening effects of the drug. Significance: Our findings reveal for the first time that UNC-45A increases MT curvature. This hints that UNC-45A-mediated MT severing could be due to the worsening of MT curvature and provide a mechanistic understanding of how this MT-severing protein may act. UNC-45A is the only MT severing protein expressed in human cancers, including paclitaxel-resistant ovarian cancer. Our finding that UNC-45A counteracts the paclitaxel-straightening effects of MTs in cells suggests an additional mechanism through which cancer cells escape drug treatment.
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35
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Petzoldt AG. Presynaptic Precursor Vesicles-Cargo, Biogenesis, and Kinesin-Based Transport across Species. Cells 2023; 12:2248. [PMID: 37759474 PMCID: PMC10527734 DOI: 10.3390/cells12182248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 08/11/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023] Open
Abstract
The faithful formation and, consequently, function of a synapse requires continuous and tightly controlled delivery of synaptic material. At the presynapse, a variety of proteins with unequal molecular properties are indispensable to compose and control the molecular machinery concerting neurotransmitter release through synaptic vesicle fusion with the presynaptic membrane. As presynaptic proteins are produced mainly in the neuronal soma, they are obliged to traffic along microtubules through the axon to reach the consuming presynapse. This anterograde transport is performed by highly specialised and diverse presynaptic precursor vesicles, membranous organelles able to transport as different proteins such as synaptic vesicle membrane and membrane-associated proteins, cytosolic active zone proteins, ion-channels, and presynaptic membrane proteins, coordinating synaptic vesicle exo- and endocytosis. This review aims to summarise and categorise the diverse and numerous findings describing presynaptic precursor cargo, mode of trafficking, kinesin-based axonal transport and the molecular mechanisms of presynaptic precursor vesicles biogenesis in both vertebrate and invertebrate model systems.
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Affiliation(s)
- Astrid G Petzoldt
- Institute for Biology and Genetics, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany
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36
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Suber Y, Alam MNA, Nakos K, Bhakt P, Spiliotis ET. Microtubule-associated septin complexes modulate kinesin and dynein motility with differential specificities. J Biol Chem 2023; 299:105084. [PMID: 37495111 PMCID: PMC10463263 DOI: 10.1016/j.jbc.2023.105084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 06/27/2023] [Accepted: 07/14/2023] [Indexed: 07/28/2023] Open
Abstract
Long-range membrane traffic is guided by microtubule-associated proteins and posttranslational modifications, which collectively comprise a traffic code. The regulatory principles of this code and how it orchestrates the motility of kinesin and dynein motors are largely unknown. Septins are a large family of GTP-binding proteins, which assemble into complexes that associate with microtubules. Using single-molecule in vitro motility assays, we tested how the microtubule-associated SEPT2/6/7, SEPT2/6/7/9, and SEPT5/7/11 complexes affect the motilities of the constitutively active kinesins KIF5C and KIF1A and the dynein-dynactin-bicaudal D (DDB) motor complex. We found that microtubule-associated SEPT2/6/7 is a potent inhibitor of DDB and KIF5C, preventing mainly their association with microtubules. SEPT2/6/7 also inhibits KIF1A by obstructing stepping along microtubules. On SEPT2/6/7/9-coated microtubules, KIF1A inhibition is dampened by SEPT9, which alone enhances KIF1A, showing that individual septin subunits determine the regulatory properties of septin complexes. Strikingly, SEPT5/7/11 differs from SEPT2/6/7, in permitting the motility of KIF1A and immobilizing DDB to the microtubule lattice. In hippocampal neurons, filamentous SEPT5 colocalizes with somatodendritic microtubules that underlie Golgi membranes and lack SEPT6. Depletion of SEPT5 disrupts Golgi morphology and polarization of Golgi ribbons into the shaft of somato-proximal dendrites, which is consistent with the tethering of DDB to microtubules by SEPT5/7/11. Collectively, these results suggest that microtubule-associated complexes have differential specificities in the regulation of the motility and positioning of microtubule motors. We posit that septins are an integral part of the microtubule-based code that spatially controls membrane traffic.
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Affiliation(s)
- Yani Suber
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Md Noor A Alam
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Konstantinos Nakos
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Priyanka Bhakt
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA
| | - Elias T Spiliotis
- Department of Biology, Drexel University, Philadelphia, Pennsylvania, USA.
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37
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Minckley TF, Salvagio LA, Fudge DH, Verhey K, Markus SM, Qin Y. Zn2+ decoration of microtubules arrests axonal transport and displaces tau, doublecortin, and MAP2C. J Cell Biol 2023; 222:e202208121. [PMID: 37326602 PMCID: PMC10276529 DOI: 10.1083/jcb.202208121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 03/31/2023] [Accepted: 05/11/2023] [Indexed: 06/17/2023] Open
Abstract
Intracellular Zn2+ concentrations increase via depolarization-mediated influx or intracellular release, but the immediate effects of Zn2+ signals on neuron function are not fully understood. By simultaneous recording of cytosolic Zn2+ and organelle motility, we find that elevated Zn2+ (IC50 ≈ 5-10 nM) reduces both lysosomal and mitochondrial motility in primary rat hippocampal neurons and HeLa cells. Using live-cell confocal microscopy and in vitro single-molecule TIRF imaging, we reveal that Zn2+ inhibits activity of motor proteins (kinesin and dynein) without disrupting their microtubule binding. Instead, Zn2+ directly binds to microtubules and selectively promotes detachment of tau, DCX, and MAP2C, but not MAP1B, MAP4, MAP7, MAP9, or p150glued. Bioinformatic predictions and structural modeling show that the Zn2+ binding sites on microtubules partially overlap with the microtubule binding sites of tau, DCX, dynein, and kinesin. Our results reveal that intraneuronal Zn2+ regulates axonal transport and microtubule-based processes by interacting with microtubules.
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Affiliation(s)
- Taylor F. Minckley
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | | | - Dylan H. Fudge
- Department of Biological Sciences, University of Denver, Denver, CO, USA
| | - Kristen Verhey
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Steven M. Markus
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO, USA
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, CO, USA
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38
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Shen Y, Ori-McKenney KM. Macromolecular Crowding Tailors the Microtubule Cytoskeleton Through Tubulin Modifications and Microtubule-Associated Proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.14.544846. [PMID: 37398431 PMCID: PMC10312695 DOI: 10.1101/2023.06.14.544846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Cells remodel their cytoskeletal networks to adapt to their environment. Here, we analyze the mechanisms utilized by the cell to tailor its microtubule landscape in response to changes in osmolarity that alter macromolecular crowding. By integrating live cell imaging, ex vivo enzymatic assays, and in vitro reconstitution, we probe the impact of acute perturbations in cytoplasmic density on microtubule-associated proteins (MAPs) and tubulin posttranslational modifications (PTMs), unraveling the molecular underpinnings of cellular adaptation via the microtubule cytoskeleton. We find that cells respond to fluctuations in cytoplasmic density by modulating microtubule acetylation, detyrosination, or MAP7 association, without differentially affecting polyglutamylation, tyrosination, or MAP4 association. These MAP-PTM combinations alter intracellular cargo transport, enabling the cell to respond to osmotic challenges. We further dissect the molecular mechanisms governing tubulin PTM specification, and find that MAP7 promotes acetylation by biasing the conformation of the microtubule lattice, and directly inhibits detyrosination. Acetylation and detyrosination can therefore be decoupled and utilized for distinct cellular purposes. Our data reveal that the MAP code dictates the tubulin code, resulting in remodeling of the microtubule cytoskeleton and alteration of intracellular transport as an integrated mechanism of cellular adaptation.
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Affiliation(s)
- Yusheng Shen
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
| | - Kassandra M Ori-McKenney
- Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA 95616, USA
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39
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Adler A, Kjaer LF, Beugelink JW, Baldus M, van Ingen H. Resonance assignments of the microtubule-binding domain of the microtubule-associated protein 7 (MAP7). BIOMOLECULAR NMR ASSIGNMENTS 2023; 17:10.1007/s12104-023-10124-8. [PMID: 37099260 DOI: 10.1007/s12104-023-10124-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 03/30/2023] [Indexed: 06/02/2023]
Abstract
The microtubule-associated protein 7 (MAP7) is a protein involved in cargo transport along microtubules (MTs) by interacting with kinesin-1 through the C-terminal kinesin-binding domain. Moreover, the protein is reported to stabilize MT, thereby playing a key role in axonal branch development. An important element for this latter function is the 112 amino-acid long N-terminal microtubule-binding domain (MTBD) of MAP7. Here we report NMR backbone and side-chain assignments that suggest a primarily alpha-helical secondary fold of this MTBD in solution. The MTBD contains a central long α-helical segment that includes a short four-residue 'hinge' sequence with decreased helicity and increased flexibility. Our data represent a first step towards analysing the complex interaction of MAP7 with MTs at an atomic level via NMR spectroscopy.
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Affiliation(s)
- Agnes Adler
- Bijvoet Center for Biomolecular Research, NMR Spectroscopy, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Lenette F Kjaer
- Bijvoet Center for Biomolecular Research, NMR Spectroscopy, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
- Institute of Structural Biology Grenoble, Grenoble, Auvergne-Rhône-Alpes, France
| | - J Wouter Beugelink
- Structural Biochemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands
| | - Marc Baldus
- Bijvoet Center for Biomolecular Research, NMR Spectroscopy, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
| | - Hugo van Ingen
- Bijvoet Center for Biomolecular Research, NMR Spectroscopy, Utrecht University, Padualaan 8, Utrecht, 3584 CH, The Netherlands.
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40
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Carmona B, Marinho HS, Matos CL, Nolasco S, Soares H. Tubulin Post-Translational Modifications: The Elusive Roles of Acetylation. BIOLOGY 2023; 12:biology12040561. [PMID: 37106761 PMCID: PMC10136095 DOI: 10.3390/biology12040561] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/27/2023] [Accepted: 04/03/2023] [Indexed: 04/29/2023]
Abstract
Microtubules (MTs), dynamic polymers of α/β-tubulin heterodimers found in all eukaryotes, are involved in cytoplasm spatial organization, intracellular transport, cell polarity, migration and division, and in cilia biology. MTs functional diversity depends on the differential expression of distinct tubulin isotypes and is amplified by a vast number of different post-translational modifications (PTMs). The addition/removal of PTMs to α- or β-tubulins is catalyzed by specific enzymes and allows combinatory patterns largely enriching the distinct biochemical and biophysical properties of MTs, creating a code read by distinct proteins, including microtubule-associated proteins (MAPs), which allow cellular responses. This review is focused on tubulin-acetylation, whose cellular roles continue to generate debate. We travel through the experimental data pointing to α-tubulin Lys40 acetylation role as being a MT stabilizer and a typical PTM of long lived MTs, to the most recent data, suggesting that Lys40 acetylation enhances MT flexibility and alters the mechanical properties of MTs, preventing MTs from mechanical aging characterized by structural damage. Additionally, we discuss the regulation of tubulin acetyltransferases/desacetylases and their impacts on cell physiology. Finally, we analyze how changes in MT acetylation levels have been found to be a general response to stress and how they are associated with several human pathologies.
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Affiliation(s)
- Bruno Carmona
- Centro de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, Lote 4.69.01, 1990-096 Lisboa, Portugal
| | - H Susana Marinho
- Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Catarina Lopes Matos
- Centro de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Sofia Nolasco
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, Lote 4.69.01, 1990-096 Lisboa, Portugal
- CIISA-Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa, Portugal
| | - Helena Soares
- Centro de Química Estrutural, Institute of Molecular Sciences, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
- Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Av. D. João II, Lote 4.69.01, 1990-096 Lisboa, Portugal
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41
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Abstract
Microtubules (MTs) form rapidly adaptable, complex intracellular networks of filaments that not only provide structural support, but also form the tracks along which motors traffic macromolecular cargos to specific sub-cellular sites. These dynamic arrays play a central role in regulating various cellular processes including cell shape and motility as well as cell division and polarization. Given their complex organization and functional importance, MT arrays are carefully controlled by many highly specialized proteins that regulate the nucleation of MT filaments at distinct sites, their dynamic growth and stability, and their engagement with other subcellular structures and cargoes destined for transport. This review focuses on recent advances in our understanding of how MTs and their regulatory proteins function, including their active targeting and exploitation, during infection by viruses that utilize a wide variety of replication strategies that occur within different cellular sub-compartments or regions of the cell.
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Affiliation(s)
- Eveline Santos da Silva
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States; HIV Clinical and Translational Research, Luxembourg Institute of Health, Department of Infection and Immunity, Esch-sur-Alzette, Luxembourg
| | - Mojgan H Naghavi
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States.
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42
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Iwanski MK, Kapitein LC. Cellular cartography: Towards an atlas of the neuronal microtubule cytoskeleton. Front Cell Dev Biol 2023; 11:1052245. [PMID: 37035244 PMCID: PMC10073685 DOI: 10.3389/fcell.2023.1052245] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 02/28/2023] [Indexed: 04/11/2023] Open
Abstract
Microtubules, one of the major components of the cytoskeleton, play a crucial role during many aspects of neuronal development and function, such as neuronal polarization and axon outgrowth. Consequently, the microtubule cytoskeleton has been implicated in many neurodevelopmental and neurodegenerative disorders. The polar nature of microtubules is quintessential for their function, allowing them to serve as tracks for long-distance, directed intracellular transport by kinesin and dynein motors. Most of these motors move exclusively towards either the plus- or minus-end of a microtubule and some have been shown to have a preference for either dynamic or stable microtubules, those bearing a particular post-translational modification or those decorated by a specific microtubule-associated protein. Thus, it becomes important to consider the interplay of these features and their combinatorial effects on transport, as well as how different types of microtubules are organized in the cell. Here, we discuss microtubule subsets in terms of tubulin isotypes, tubulin post-translational modifications, microtubule-associated proteins, microtubule stability or dynamicity, and microtubule orientation. We highlight techniques used to study these features of the microtubule cytoskeleton and, using the information from these studies, try to define the composition, role, and organization of some of these subsets in neurons.
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Affiliation(s)
| | - Lukas C. Kapitein
- Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
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43
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Canty JT, Hensley A, Aslan M, Jack A, Yildiz A. TRAK adaptors regulate the recruitment and activation of dynein and kinesin in mitochondrial transport. Nat Commun 2023; 14:1376. [PMID: 36914620 PMCID: PMC10011603 DOI: 10.1038/s41467-023-36945-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 02/23/2023] [Indexed: 03/16/2023] Open
Abstract
Mitochondrial transport along microtubules is mediated by Miro1 and TRAK adaptors that recruit kinesin-1 and dynein-dynactin. To understand how these opposing motors are regulated during mitochondrial transport, we reconstitute the bidirectional transport of Miro1/TRAK along microtubules in vitro. We show that the coiled-coil domain of TRAK activates dynein-dynactin and enhances the motility of kinesin-1 activated by its cofactor MAP7. We find that TRAK adaptors that recruit both motors move towards kinesin-1's direction, whereas kinesin-1 is excluded from binding TRAK transported by dynein-dynactin, avoiding motor tug-of-war. We also test the predictions of the models that explain how mitochondrial transport stalls in regions with elevated Ca2+. Transport of Miro1/TRAK by kinesin-1 is not affected by Ca2+. Instead, we demonstrate that the microtubule docking protein syntaphilin induces resistive forces that stall kinesin-1 and dynein-driven motility. Our results suggest that mitochondrial transport stalls by Ca2+-mediated recruitment of syntaphilin to the mitochondrial membrane, not by disruption of the transport machinery.
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Affiliation(s)
- John T Canty
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA, 94720, USA.
- Department of Cancer Immunology, Genentech Inc., 1 DNA Way, 94080, South San Francisco, CA, USA.
| | - Andrew Hensley
- Physics Department, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Merve Aslan
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Amanda Jack
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA, 94720, USA
| | - Ahmet Yildiz
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA, 94720, USA.
- Physics Department, University of California at Berkeley, Berkeley, CA, 94720, USA.
- Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA, 94720, USA.
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44
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Redpath GMI, Ananthanarayanan V. Endosomal sorting sorted - motors, adaptors and lessons from in vitro and cellular studies. J Cell Sci 2023; 136:292583. [PMID: 36861885 DOI: 10.1242/jcs.260749] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
Motor proteins are key players in exerting spatiotemporal control over the intracellular location of membrane-bound compartments, including endosomes containing cargo. In this Review, we focus on how motors and their cargo adaptors regulate positioning of cargoes from the earliest stages of endocytosis and through the two main intracellular itineraries: (1) degradation at the lysosome or (2) recycling back to the plasma membrane. In vitro and cellular (in vivo) studies on cargo transport thus far have typically focussed independently on either the motor proteins and adaptors, or membrane trafficking. Here, we will discuss recent studies to highlight what is known about the regulation of endosomal vesicle positioning and transport by motors and cargo adaptors. We also emphasise that in vitro and cellular studies are often performed at different scales, from single molecules to whole organelles, with the aim to provide a perspective on the unified principles of motor-driven cargo trafficking in living cells that can be learned from these differing scales.
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Affiliation(s)
- Gregory M I Redpath
- EMBL Australia Node in Single Molecule Science, Department of Molecular Medicine, School of Biomedical Sciences, The University of New South Wales, Sydney 2052, Australia
| | - Vaishnavi Ananthanarayanan
- EMBL Australia Node in Single Molecule Science, Department of Molecular Medicine, School of Biomedical Sciences, The University of New South Wales, Sydney 2052, Australia
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45
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Tran MV, Ferguson JW, Cote LE, Khuntsariya D, Fetter RD, Wang JT, Wellard SR, Sallee MD, Genova M, Eskinazi S, Magiera MM, Janke C, Stearns T, Lansky Z, Shen K, Magescas J, Feldman JL. MAP9/MAPH-9 supports axonemal microtubule doublets and modulates motor movement. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529616. [PMID: 36865107 PMCID: PMC9980146 DOI: 10.1101/2023.02.23.529616] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Microtubule doublets (MTDs) are a well conserved compound microtubule structure found primarily in cilia. However, the mechanisms by which MTDs form and are maintained in vivo remain poorly understood. Here, we characterize microtubule-associated protein 9 (MAP9) as a novel MTD-associated protein. We demonstrate that C. elegans MAPH-9, a MAP9 homolog, is present during MTD assembly and localizes exclusively to MTDs, a preference that is in part mediated by tubulin polyglutamylation. Loss of MAPH-9 caused ultrastructural MTD defects, dysregulated axonemal motor velocity, and perturbed cilia function. As we found that the mammalian ortholog MAP9 localized to axonemes in cultured mammalian cells and mouse tissues, we propose that MAP9/MAPH-9 plays a conserved role in supporting the structure of axonemal MTDs and regulating ciliary motors.
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46
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Zocchi R, Compagnucci C, Bertini E, Sferra A. Deciphering the Tubulin Language: Molecular Determinants and Readout Mechanisms of the Tubulin Code in Neurons. Int J Mol Sci 2023; 24:ijms24032781. [PMID: 36769099 PMCID: PMC9917122 DOI: 10.3390/ijms24032781] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/17/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Microtubules (MTs) are dynamic components of the cell cytoskeleton involved in several cellular functions, such as structural support, migration and intracellular trafficking. Despite their high similarity, MTs have functional heterogeneity that is generated by the incorporation into the MT lattice of different tubulin gene products and by their post-translational modifications (PTMs). Such regulations, besides modulating the tubulin composition of MTs, create on their surface a "biochemical code" that is translated, through the action of protein effectors, into specific MT-based functions. This code, known as "tubulin code", plays an important role in neuronal cells, whose highly specialized morphologies and activities depend on the correct functioning of the MT cytoskeleton and on its interplay with a myriad of MT-interacting proteins. In recent years, a growing number of mutations in genes encoding for tubulins, MT-interacting proteins and enzymes that post-translationally modify MTs, which are the main players of the tubulin code, have been linked to neurodegenerative processes or abnormalities in neural migration, differentiation and connectivity. Nevertheless, the exact molecular mechanisms through which the cell writes and, downstream, MT-interacting proteins decipher the tubulin code are still largely uncharted. The purpose of this review is to describe the molecular determinants and the readout mechanisms of the tubulin code, and briefly elucidate how they coordinate MT behavior during critical neuronal events, such as neuron migration, maturation and axonal transport.
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Affiliation(s)
- Riccardo Zocchi
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
| | - Claudia Compagnucci
- Molecular Genetics and Functional Genomics, Bambino Gesù Children’s Research Hospital, IRCCS, 00146 Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
| | - Antonella Sferra
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
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47
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Dullovi A, Ozgencil M, Rajvee V, Tse WY, Cutillas PR, Martin SA, Hořejší Z. Microtubule-associated proteins MAP7 and MAP7D1 promote DNA double-strand break repair in the G1 cell cycle phase. iScience 2023; 26:106107. [PMID: 36852271 PMCID: PMC9958362 DOI: 10.1016/j.isci.2023.106107] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 12/12/2022] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
The DNA-damage response is a complex signaling network that guards genomic integrity. The microtubule cytoskeleton is involved in the repair of DNA double-strand breaks; however, little is known about which cytoskeleton-related proteins are involved in DNA repair and how. Using quantitative proteomics, we discovered that microtubule associated proteins MAP7 and MAP7D1 interact with several DNA repair proteins including DNA double-strand break repair proteins RAD50, BRCA1 and 53BP1. We observed that downregulation of MAP7 and MAP7D1 leads to increased phosphorylation of p53 after γ-irradiation. Moreover, we determined that the downregulation of MAP7D1 leads to a strong G1 arrest and that the downregulation of MAP7 and MAP7D1 in G1 arrested cells negatively affects DNA repair, recruitment of RAD50 to chromatin and localization of 53BP1 to the sites of damage. These findings describe for the first time a novel function of MAP7 and MAP7D1 in cell cycle regulation and repair of DNA double-strand breaks.
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Affiliation(s)
- Arlinda Dullovi
- Centre for Cancer Cell & Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Meryem Ozgencil
- Centre for Cancer Cell & Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Vinothini Rajvee
- Mass Spectrometry Laboratory, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Wai Yiu Tse
- Centre for Cancer Cell & Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Pedro R. Cutillas
- Centre for Genomics & Computational Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Sarah A. Martin
- Centre for Cancer Cell & Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK
| | - Zuzana Hořejší
- Centre for Cancer Cell & Molecular Biology, Barts Cancer Institute, Queen Mary University of London, Charterhouse Square, London EC1M 6BQ, UK,Corresponding author
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48
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Li Q, Ferrare JT, Silver J, Wilson JO, Arteaga-Castaneda L, Qiu W, Vershinin M, King SJ, Neuman KC, Xu J. Cholesterol in the cargo membrane amplifies tau inhibition of kinesin-1-based transport. Proc Natl Acad Sci U S A 2023; 120:e2212507120. [PMID: 36626558 PMCID: PMC9934065 DOI: 10.1073/pnas.2212507120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 12/08/2022] [Indexed: 01/11/2023] Open
Abstract
Intracellular cargos are often membrane-enclosed and transported by microtubule-based motors in the presence of microtubule-associated proteins (MAPs). Whereas increasing evidence reveals how MAPs impact the interactions between motors and microtubules, critical questions remain about the impact of the cargo membrane on transport. Here we combined in vitro optical trapping with theoretical approaches to determine the effect of a lipid cargo membrane on kinesin-based transport in the presence of MAP tau. Our results demonstrate that attaching kinesin to a fluid lipid membrane reduces the inhibitory effect of tau on kinesin. Moreover, adding cholesterol, which reduces kinesin diffusion in the cargo membrane, amplifies the inhibitory effect of tau on kinesin binding in a dosage-dependent manner. We propose that reduction of kinesin diffusion in the cargo membrane underlies the effect of cholesterol on kinesin binding in the presence of tau, and we provide a simple model for this proposed mechanism. Our study establishes a direct link between cargo membrane cholesterol and MAP-based regulation of kinesin-1. The cholesterol effects uncovered here may more broadly extend to other lipid alterations that impact motor diffusion in the cargo membrane, including those associated with aging and neurological diseases.
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Affiliation(s)
- Qiaochu Li
- Department of Physics, University of California, Merced, CA95343
| | - James T. Ferrare
- Laboratory of Single Molecule Biophysics, National Heart, Lung and Blood Institute, NIH, Bethesda, MD20892
| | - Jonathan Silver
- Laboratory of Single Molecule Biophysics, National Heart, Lung and Blood Institute, NIH, Bethesda, MD20892
| | - John O. Wilson
- Department of Physics, University of California, Merced, CA95343
| | | | - Weihong Qiu
- Department of Physics, Oregon State University, Corvallis, OR97331
| | - Michael Vershinin
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT84112
| | - Stephen J. King
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL32827
| | - Keir C. Neuman
- Laboratory of Single Molecule Biophysics, National Heart, Lung and Blood Institute, NIH, Bethesda, MD20892
| | - Jing Xu
- Department of Physics, University of California, Merced, CA95343
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49
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Beaudet D, Hendricks AG. Reconstitution of Organelle Transport Along Microtubules In Vitro. Methods Mol Biol 2023; 2623:113-132. [PMID: 36602683 DOI: 10.1007/978-1-0716-2958-1_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this chapter, we describe methods for reconstituting and analyzing the transport of isolated endogenous cargoes in vitro. Intracellular cargoes are transported along microtubules by teams of kinesin and dynein motors and their cargo-specific adaptor proteins. Observations from living cells show that organelles and vesicular cargoes exhibit diverse motility characteristics. Yet, our knowledge of the molecular mechanisms by which intracellular transport is regulated is not well understood. Here, we describe step-by-step protocols for the extraction of phagosomes from cells at different stages of maturation, and reconstitution of their motility along microtubules in vitro. Quantitative immunofluorescence and photobleaching techniques are also described to measure the number of motors and adaptor proteins on these isolated cargoes. In addition, we describe techniques for tracking the motility of isolated cargoes along microtubules using TIRF microscopy and quantitative force measurements using an optical trap. These methods enable us to study how the sets of motors and adaptors that drive the transport of endogenous cargoes regulate their trafficking in cells.
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Affiliation(s)
- Daniel Beaudet
- Department of Bioengineering, McGill University, Montreal, QC, Canada
| | - Adam G Hendricks
- Department of Bioengineering, McGill University, Montreal, QC, Canada.
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50
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Fenton AR, Cason SE, Holzbaur ELF. Single-Molecule Studies of Motor Adaptors Using Cell Lysates. Methods Mol Biol 2023; 2623:97-111. [PMID: 36602682 DOI: 10.1007/978-1-0716-2958-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Long-range transport of organelles and other cellular cargoes along microtubules is driven by kinesin and dynein motor proteins in complex with cargo-specific adaptors. While some adaptors interact exclusively with a single motor, other adaptors interact with both kinesin and dynein motors. However, the mechanisms by which bidirectional motor adaptors coordinate opposing microtubule motors are not fully understood. While single-molecule studies of adaptors using purified proteins can provide key insight into motor adaptor function, these studies may be limited by the absence of cellular factors that regulate or coordinate motor function. As a result, motility assays using cell lysates have been developed to gain insight into motor adaptor function in a more physiological context. These assays are a powerful means to dissect the regulation of motor adaptors as cell lysates contain endogenous microtubule motors and additional factors that regulate motor function. Further, this system is highly tractable as individual proteins can readily be added or removed via overexpression or knockdown in cells. Here, we describe a protocol for in vitro reconstitution of motor-driven transport along dynamic microtubules at single-molecule resolution using total internal reflection fluorescence microscopy of cell lysates.
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Affiliation(s)
- Adam R Fenton
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Sydney E Cason
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.,Neuroscience Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. .,Cell and Molecular Biology Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. .,Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. .,Neuroscience Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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