1
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Segura-Roman A, Citron YR, Shin M, Sindoni N, Maya-Romero A, Rapp S, Goul C, Mancias JD, Zoncu R. Autophagosomes coordinate an AKAP11-dependent regulatory checkpoint that shapes neuronal PKA signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.06.606738. [PMID: 39211170 PMCID: PMC11361107 DOI: 10.1101/2024.08.06.606738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Protein Kinase A (PKA) is regulated spatially and temporally via scaffolding of its catalytic (Cα/β) and regulatory (RI/RII) subunits by the A-kinase-anchoring proteins (AKAP). PKA engages in poorly understood interactions with autophagy, a key degradation pathway for neuronal cell homeostasis, partly via its AKAP11 scaffold. Mutations in AKAP11 drive schizophrenia and bipolar disorders (SZ-BP) through unknown mechanisms. Through proteomic-based analysis of immunopurified lysosomes, we identify the Cα-RIα-AKAP11 holocomplex as a prominent autophagy-associated protein kinase complex. AKAP11 scaffolds Cα-RIα to the autophagic machinery via its LC3-interacting region (LIR), enabling both PKA regulation by upstream signals, and its autophagy-dependent degradation. We identify Ser83 on the RIα linker-hinge region as an AKAP11-dependent phospho-residue that modulates RIα-Cα binding and cAMP-induced PKA activation. Decoupling AKAP11-PKA from autophagy alters Ser83 phosphorylation, supporting an autophagy-dependent checkpoint for PKA signaling. Ablating AKAP11 in induced pluripotent stem cell-derived neurons reveals dysregulation of multiple pathways for neuronal homeostasis. Thus, the autophagosome is a novel platform that modulate PKA signaling, providing a possible mechanistic link to SZ/BP pathophysiology.
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2
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Reggi E, Kaiser S, Sahnane N, Uccella S, La Rosa S, Diviani D. AKAP2-anchored protein phosphatase 1 controls prostatic neuroendocrine carcinoma cell migration and invasion. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166916. [PMID: 37827203 DOI: 10.1016/j.bbadis.2023.166916] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 09/20/2023] [Accepted: 10/06/2023] [Indexed: 10/14/2023]
Abstract
Prostate cancer (PC) is the second leading cause of cancer-related death in men. The growth of primary prostate cancer cells relies on circulating androgens and thus the standard therapy for the treatment of localized and advanced PC is the androgen deprivation therapy. Prostatic neuroendocrine carcinoma (PNEC) is an aggressive and highly metastatic subtype of prostate cancer, which displays poor prognosis and high lethality. Most of PNECs develop from prostate adenocarcinoma in response to androgen deprivation therapy, however the mechanisms involved in this transition and in the elevated biological aggressiveness of PNECs are poorly defined. Our current findings indicate that AKAP2 expression is dramatically upregulated in PNECs as compared to non-cancerous prostate tissues. Using a PNEC cell model, we could show that AKAP2 is localized both intracellularly and at the cell periphery where it colocalizes with F-actin. AKAP2 and F-actin interact directly through a newly identified actin-binding domain located on AKAP2. RNAi-mediated silencing of AKAP2 promotes the phosphorylation and deactivation of cofilin, a protein involved in actin turnover. This effect correlates with a significant reduction in cell migration and invasion. Co-immunoprecipitation experiments and proximity ligation assays revealed that AKAP2 forms a complex with the catalytic subunit of protein phosphatase 1 (PP1) in PNECs. Importantly, AKAP2-mediated anchoring of PP1 to the actin cytoskeleton regulates cofilin dephosphorylation and activation, which, in turn, enhances F-actin dynamics and favors migration and invasion. In conclusion, this study identified AKAP2 as an anchoring protein overexpressed in PNECs that controls cancer cell invasive properties by regulating cofilin phosphorylation.
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Affiliation(s)
- Erica Reggi
- Department of Biomedical Sciences, Faculty of Biology et Medicine, University of Lausanne, 1011 Lausanne, Switzerland
| | - Simon Kaiser
- Department of Biomedical Sciences, Faculty of Biology et Medicine, University of Lausanne, 1011 Lausanne, Switzerland
| | - Nora Sahnane
- Unit of Pathology, Department of Oncology, ASST Sette Laghi, Varese, Italy
| | - Silvia Uccella
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; Pathology Service, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), Humanitas Research Hospital, Milan, Italy
| | - Stefano La Rosa
- Unit of Pathology, Department of Oncology, ASST Sette Laghi, Varese, Italy; Unit of Pathology, Department of Medicine and Technological Innovation, University of Insubria, Varese, Italy
| | - Dario Diviani
- Department of Biomedical Sciences, Faculty of Biology et Medicine, University of Lausanne, 1011 Lausanne, Switzerland.
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3
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Gopalan J, Omar MH, Roy A, Cruz NM, Falcone J, Jones KN, Forbush KA, Himmelfarb J, Freedman BS, Scott JD. Targeting an anchored phosphatase-deacetylase unit restores renal ciliary homeostasis. eLife 2021; 10:e67828. [PMID: 34250905 PMCID: PMC8291974 DOI: 10.7554/elife.67828] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 07/11/2021] [Indexed: 11/13/2022] Open
Abstract
Pathophysiological defects in water homeostasis can lead to renal failure. Likewise, common genetic disorders associated with abnormal cytoskeletal dynamics in the kidney collecting ducts and perturbed calcium and cAMP signaling in the ciliary compartment contribute to chronic kidney failure. We show that collecting ducts in mice lacking the A-Kinase anchoring protein AKAP220 exhibit enhanced development of primary cilia. Mechanistic studies reveal that AKAP220-associated protein phosphatase 1 (PP1) mediates this phenotype by promoting changes in the stability of histone deacetylase 6 (HDAC6) with concomitant defects in actin dynamics. This proceeds through a previously unrecognized adaptor function for PP1 as all ciliogenesis and cytoskeletal phenotypes are recapitulated in mIMCD3 knock-in cells expressing a phosphatase-targeting defective AKAP220-ΔPP1 mutant. Pharmacological blocking of local HDAC6 activity alters cilia development and reduces cystogenesis in kidney-on-chip and organoid models. These findings identify the AKAP220-PPI-HDAC6 pathway as a key effector in primary cilia development.
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Affiliation(s)
- Janani Gopalan
- Department of Pharmacology, University of WashingtonSeattleUnited States
| | - Mitchell H Omar
- Department of Pharmacology, University of WashingtonSeattleUnited States
| | - Ankita Roy
- Kidney Research Institute, Division of Nephrology, Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
- Institute for Stem Cell and Regenerative Medicine, University of WashingtonSeattleUnited States
| | - Nelly M Cruz
- Kidney Research Institute, Division of Nephrology, Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
- Institute for Stem Cell and Regenerative Medicine, University of WashingtonSeattleUnited States
| | - Jerome Falcone
- Department of Pharmacology, University of WashingtonSeattleUnited States
| | - Kiana N Jones
- Department of Pharmacology, University of WashingtonSeattleUnited States
| | | | - Jonathan Himmelfarb
- Kidney Research Institute, Division of Nephrology, Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
| | - Benjamin S Freedman
- Kidney Research Institute, Division of Nephrology, Department of Laboratory Medicine and Pathology, University of WashingtonSeattleUnited States
- Institute for Stem Cell and Regenerative Medicine, University of WashingtonSeattleUnited States
| | - John D Scott
- Department of Pharmacology, University of WashingtonSeattleUnited States
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4
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Kinase-anchoring proteins in ciliary signal transduction. Biochem J 2021; 478:1617-1629. [PMID: 33909027 DOI: 10.1042/bcj20200869] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/23/2021] [Accepted: 03/29/2021] [Indexed: 12/16/2022]
Abstract
Historically, the diffusion of chemical signals through the cell was thought to occur within a cytoplasmic soup bounded by the plasma membrane. This theory was predicated on the notion that all regulatory enzymes are soluble and moved with a Brownian motion. Although enzyme compartmentalization was initially rebuffed by biochemists as a 'last refuge of a scoundrel', signal relay through macromolecular complexes is now accepted as a fundamental tenet of the burgeoning field of spatial biology. A-Kinase anchoring proteins (AKAPs) are prototypic enzyme-organizing elements that position clusters of regulatory proteins at defined subcellular locations. In parallel, the primary cilium has gained recognition as a subcellular mechanosensory organelle that amplifies second messenger signals pertaining to metazoan development. This article highlights advances in our understanding of AKAP signaling within the primary cilium and how defective ciliary function contributes to an increasing number of diseases known as ciliopathies.
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5
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AKAP79/150 coordinates leptin-induced PKA signaling to regulate K ATP channel trafficking in pancreatic β-cells. J Biol Chem 2021; 296:100442. [PMID: 33617875 PMCID: PMC8010710 DOI: 10.1016/j.jbc.2021.100442] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/11/2021] [Accepted: 02/17/2021] [Indexed: 01/21/2023] Open
Abstract
The adipocyte hormone leptin regulates glucose homeostasis both centrally and peripherally. A key peripheral target is the pancreatic β-cell, which secretes insulin upon glucose stimulation. Leptin is known to suppress glucose-stimulated insulin secretion by promoting trafficking of KATP channels to the β-cell surface, which increases K+ conductance and causes β-cell hyperpolarization. We have previously shown that leptin-induced KATP channel trafficking requires protein kinase A (PKA)-dependent actin remodeling. However, whether PKA is a downstream effector of leptin signaling or PKA plays a permissive role is unknown. Using FRET-based reporters of PKA activity, we show that leptin increases PKA activity at the cell membrane and that this effect is dependent on N-methyl-D-aspartate receptors, CaMKKβ, and AMPK, which are known to be involved in the leptin signaling pathway. Genetic knockdown and rescue experiments reveal that the increased PKA activity upon leptin stimulation requires the membrane-targeted PKA-anchoring protein AKAP79/150, indicating that PKA activated by leptin is anchored to AKAP79/150. Interestingly, disrupting protein phosphatase 2B (PP2B) anchoring to AKAP79/150, known to elevate basal PKA signaling, leads to increased surface KATP channels even in the absence of leptin stimulation. Our findings uncover a novel role of AKAP79/150 in coordinating leptin and PKA signaling to regulate KATP channel trafficking in β-cells, hence insulin secretion. The study further advances our knowledge of the downstream signaling events that may be targeted to restore insulin secretion regulation in β-cells defective in leptin signaling, such as those from obese individuals with type 2 diabetes.
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6
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Peng X, Wang T, Gao H, Yue X, Bian W, Mei J, Zhang Y. The interplay between IQGAP1 and small GTPases in cancer metastasis. Biomed Pharmacother 2021; 135:111243. [PMID: 33434854 DOI: 10.1016/j.biopha.2021.111243] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/27/2020] [Accepted: 12/31/2020] [Indexed: 01/07/2023] Open
Abstract
The metastatic spread of tumor cells to distant anatomical locations is a critical cause for disease progression and leads to more than 90 % of cancer-related deaths. IQ motif-containing GTPase-activating protein 1 (IQGAP1), a prominent regulator in the cancer metastasis process, is a scaffold protein that interacts with components of the cytoskeleton. As a critical node within the small GTPase network, IQGAP1 acts as a binding partner of several small GTPases, which in turn function as molecular switches to control most cellular processes, including cell migration and invasion. Given the significant interaction between IQGAP1 and small GTPases in cancer metastasis, we briefly elucidate the role of IQGAP1 in regulating cancer metastasis and the varied interactions existing between IQGAP1 and small GTPases. In addition, the potential regulators for IQGAP1 activity and its interaction with small GTPases are also incorporated in this review. Overall, we comprehensively summarize the role of IQGAP1 in cancer tumorigenicity and metastasis, which may be a potential anti-tumor target to restrain cancer progression.
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Affiliation(s)
- Xiafeng Peng
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Tiejun Wang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
| | - Han Gao
- School of Medicine, Jiangnan University, Wuxi, 214122, China.
| | - Xin Yue
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Weiqi Bian
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Jie Mei
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; Wuxi Clinical Medical College, Nanjing Medical University, Wuxi, 214023, China.
| | - Yan Zhang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
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7
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Hedman AC, Li Z, Gorisse L, Parvathaneni S, Morgan CJ, Sacks DB. IQGAP1 binds AMPK and is required for maximum AMPK activation. J Biol Chem 2020; 296:100075. [PMID: 33191271 PMCID: PMC7948462 DOI: 10.1074/jbc.ra120.016193] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/15/2020] [Indexed: 12/25/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a fundamental component of a protein kinase cascade that is an energy sensor. AMPK maintains energy homeostasis in the cell by promoting catabolic and inhibiting anabolic pathways. Activation of AMPK requires phosphorylation by the liver kinase B1 or by the Ca2+/calmodulin-dependent protein kinase 2 (CaMKK2). The scaffold protein IQGAP1 regulates intracellular signaling pathways, such as the mitogen-activated protein kinase and AKT signaling cascades. Recent work implicates the participation of IQGAP1 in metabolic function, but the molecular mechanisms underlying these effects are poorly understood. Here, using several approaches including binding analysis with fusion proteins, siRNA-mediated gene silencing, RT-PCR, and knockout mice, we investigated whether IQGAP1 modulates AMPK signaling. In vitro analysis reveals that IQGAP1 binds directly to the α1 subunit of AMPK. In addition, we observed a direct interaction between IQGAP1 and CaMKK2, which is mediated by the IQ domain of IQGAP1. Both CaMKK2 and AMPK associate with IQGAP1 in cells. The ability of metformin and increased intracellular free Ca2+ concentrations to activate AMPK is reduced in cells lacking IQGAP1. Importantly, Ca2+-stimulated AMPK phosphorylation was rescued by re-expression of IQGAP1 in IQGAP1-null cell lines. Comparison of the fasting response in wild-type and IQGAP1-null mice revealed that transcriptional regulation of the gluconeogenesis genes PCK1 and G6PC and the fatty acid synthesis genes FASN and ACC1 is impaired in IQGAP1-null mice. Our data disclose a previously unidentified functional interaction between IQGAP1 and AMPK and suggest that IQGAP1 modulates AMPK signaling.
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Affiliation(s)
- Andrew C Hedman
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Zhigang Li
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Laëtitia Gorisse
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Swetha Parvathaneni
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Chase J Morgan
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - David B Sacks
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland, USA.
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8
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Omar MH, Scott JD. AKAP Signaling Islands: Venues for Precision Pharmacology. Trends Pharmacol Sci 2020; 41:933-946. [PMID: 33082006 DOI: 10.1016/j.tips.2020.09.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/19/2022]
Abstract
Regulatory enzymes often have different roles in distinct subcellular compartments. Yet, most drugs indiscriminately saturate the cell. Thus, subcellular drug-delivery holds promise as a means to reduce off-target pharmacological effects. A-kinase anchoring proteins (AKAPs) sequester combinations of signaling enzymes within subcellular microdomains. Targeting drugs to these 'signaling islands' offers an opportunity for more precise delivery of therapeutics. Here, we review mechanisms that bestow protein kinase A (PKA) versatility inside the cell, appraise recent advances in exploiting AKAPs as platforms for precision pharmacology, and explore the impact of methodological innovations on AKAP research.
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Affiliation(s)
- Mitchell H Omar
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, WA, 98195, USA.
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9
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Bucko PJ, Scott JD. Drugs That Regulate Local Cell Signaling: AKAP Targeting as a Therapeutic Option. Annu Rev Pharmacol Toxicol 2020; 61:361-379. [PMID: 32628872 DOI: 10.1146/annurev-pharmtox-022420-112134] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells respond to environmental cues by mobilizing signal transduction cascades that engage protein kinases and phosphoprotein phosphatases. Correct organization of these enzymes in space and time enables the efficient and precise transmission of chemical signals. The cyclic AMP-dependent protein kinase A is compartmentalized through its association with A-kinase anchoring proteins (AKAPs). AKAPs are a family of multivalent scaffolds that constrain signaling enzymes and effectors at subcellular locations to drive essential physiological events. More recently, it has been recognized that defective signaling in certain endocrine disorders and cancers proceeds through pathological AKAP complexes. Consequently, pharmacologically targeting these macromolecular complexes unlocks new therapeutic opportunities for a growing number of clinical indications. This review highlights recent findings on AKAP signaling in disease, particularly in certain cancers, and offers an overview of peptides and small molecules that locally regulate AKAP-binding partners.
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Affiliation(s)
- Paula J Bucko
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
| | - John D Scott
- Department of Pharmacology, University of Washington, Seattle, Washington 98195, USA; ,
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10
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Freitas MJ, Silva JV, Brothag C, Regadas-Correia B, Fardilha M, Vijayaraghavan S. Isoform-specific GSK3A activity is negatively correlated with human sperm motility. Mol Hum Reprod 2020; 25:171-183. [PMID: 30824926 DOI: 10.1093/molehr/gaz009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 01/29/2019] [Accepted: 02/19/2019] [Indexed: 01/04/2023] Open
Abstract
In mouse and bovine sperm, GSK3 activity is inversely proportional to motility. Targeted disruption of the GSK3A gene in testis results in normal spermatogenesis, but mature sperm present a reduced motility, rendering male mice infertile. On the other hand, GSK3B testis-specific KO is fertile. Yet in human sperm, an isoform-specific correlation between GSK3A and sperm motility was never established. In order to analyze GSK3 function in human sperm motility, normospermic and asthenozoospermic samples from adult males were used to correlate GSK3 expression and activity levels with human sperm motility profiles. Moreover, testicular and sperm GSK3 interactomes were identified using a yeast two-hybrid screen and coimmunoprecipitation, respectively. An extensive in-silico analysis of the GSK3 interactome was performed. The results proved that inhibited GSK3A (serine phosphorylated) presents a significant strong positive correlation (r = 0.822, P = 0.023) with the percentage of progressive human sperm, whereas inhibited GSK3B is not significantly correlated with sperm motility (r = 0.577, P = 0.175). The importance of GSK3 in human sperm motility was further reinforced by in-silico analysis of the GSK3 interactome, which revealed a high level of involvement of GSK3 interactors in sperm motility-related functions. The limitation of techniques used for GSK3 interactome identification can be a drawback, since none completely mimics the physiological environment. Our findings prove that human sperm motility relies on isoform-specific functions of GSK3A within this cell. Given the reported relevance of GSK3 protein-protein interactions in sperm motility, we hypothesized that they stand as potential targets for male contraceptive strategies based on sperm motility modulation.
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Affiliation(s)
- M J Freitas
- Signal Transduction Laboratory, Institute for Research in Biomedicine-iBiMED, Medical Sciences Department, University of Aveiro, Aveiro, Portugal
| | - J V Silva
- Signal Transduction Laboratory, Institute for Research in Biomedicine-iBiMED, Medical Sciences Department, University of Aveiro, Aveiro, Portugal.,Reproductive Genetics & Embryo-fetal Development Group, Institute for Innovation and Health Research (I3S), University of Porto, Porto, Portugal.,Department of Microscopy, Laboratory of Cell Biology, and Unit for Multidisciplinary Research in Biomedicine (UMIB), Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - C Brothag
- Kent State University, Kent, OH, USA
| | - B Regadas-Correia
- CNC.IBILI-Institute for Biomedical Imaging and Life Sciences, Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CIBIT-Coimbra Institute for Biomedical Imaging and Translational Research, University of Coimbra, Coimbra, Portugal.,Department Quantitative Methods and Information and Management Systems, Coimbra Business School, Coimbra, Portugal
| | - M Fardilha
- Signal Transduction Laboratory, Institute for Research in Biomedicine-iBiMED, Medical Sciences Department, University of Aveiro, Aveiro, Portugal
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11
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Stafuzza NB, Silva RMDO, Fragomeni BDO, Masuda Y, Huang Y, Gray K, Lourenco DAL. A genome-wide single nucleotide polymorphism and copy number variation analysis for number of piglets born alive. BMC Genomics 2019; 20:321. [PMID: 31029102 PMCID: PMC6487013 DOI: 10.1186/s12864-019-5687-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 04/11/2019] [Indexed: 12/19/2022] Open
Abstract
Background In this study we integrated the CNV (copy number variation) and WssGWAS (weighted single-step approach for genome-wide association) analyses to increase the knowledge about number of piglets born alive, an economically important reproductive trait with significant impact on production efficiency of pigs. Results A total of 3892 samples were genotyped with the Porcine SNP80 BeadChip. After quality control, a total of 57,962 high-quality SNPs from 3520 Duroc pigs were retained. The PennCNV algorithm identified 46,118 CNVs, which were aggregated by overlapping in 425 CNV regions (CNVRs) ranging from 2.5 Kb to 9718.4 Kb and covering 197 Mb (~ 7.01%) of the pig autosomal genome. The WssGWAS identified 16 genomic regions explaining more than 1% of the additive genetic variance for number of piglets born alive. The overlap between CNVR and WssGWAS analyses identified common regions on SSC2 (4.2–5.2 Mb), SSC3 (3.9–4.9 Mb), SSC12 (56.6–57.6 Mb), and SSC17 (17.3–18.3 Mb). Those regions are known for harboring important causative variants for pig reproductive traits based on their crucial functions in fertilization, development of gametes and embryos. Functional analysis by the Panther software identified 13 gene ontology biological processes significantly represented in this study such as reproduction, developmental process, cellular component organization or biogenesis, and immune system process, which plays relevant roles in swine reproductive traits. Conclusion Our research helps to improve the understanding of the genetic architecture of number of piglets born alive, given that the combination of GWAS and CNV analyses allows for a more efficient identification of the genomic regions and biological processes associated with this trait in Duroc pigs. Pig breeding programs could potentially benefit from a more accurate discovery of important genomic regions. Electronic supplementary material The online version of this article (10.1186/s12864-019-5687-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nedenia Bonvino Stafuzza
- Department of Exact Science, School of Agricultural and Veterinarian Sciences (FCAV), Sao Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil. .,Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA.
| | - Rafael Medeiros de Oliveira Silva
- Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA.,National Center for Cool and Cold Water Aquaculture (NCCCWA), Agricultural Research Service, United States Department of Agriculture, Kearneysville, WV, USA
| | | | - Yutaka Masuda
- Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA
| | - Yijian Huang
- Smithfield Premium Genetics Group, Rose Hill, NC, USA
| | - Kent Gray
- Smithfield Premium Genetics Group, Rose Hill, NC, USA
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12
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Kim M, Lee Y, Yoo Y, Choi J, Kim H, Kang C, Yu J, Moon S, Kim A, Kim C. Exogenous CLASP2 protein treatment enhances wound healing
in vitro
and
in vivo. Wound Repair Regen 2019; 27:345-359. [DOI: 10.1111/wrr.12713] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 11/16/2018] [Accepted: 11/27/2018] [Indexed: 12/31/2022]
Affiliation(s)
- MiJung Kim
- Division of Life SciencesCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
| | - You‐Sun Lee
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
| | - Yun‐Mi Yoo
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
| | - Jong‐Jin Choi
- Department of Stem Cell BiologySchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Ha‐Na Kim
- Department of Stem Cell BiologySchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Changhee Kang
- Department of Stem Cell BiologySchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Ji‐Min Yu
- R&D DivisionCHA Biotech Co. Ltd. 521 CHABIO Complex, 335 Pangyo‐ro, Bundang‐gu Gyeonggi‐Do South Korea
| | - Sung‐Hwan Moon
- Department of MedicineSchool of Medicine, Konkuk University 120 Neungdong‐ro, Gwangjin‐gu, Seoul 143‐701 South Korea
| | - Aeri Kim
- College of Pharmacy, CHA University 521 CHABIO Complex, 335 Pangyo‐ro, Bundang‐gu Gyeonggi‐Do South Korea
| | - Chan‐Wha Kim
- Division of Life SciencesCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
- Department of BiotechnologyCollege of Life Sciences and Biotechnology, Korea University 145 Anam‐dong, Sungbuk‐ku, Seoul 136701 South Korea
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13
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Wang P, Gong X, Guan P, Ji D, Du L, Xu D, Liu Y. Site-specific expression of IQGAP1 in human nephrons. J Mol Histol 2019; 50:119-127. [PMID: 30659402 DOI: 10.1007/s10735-019-09811-5] [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: 10/28/2018] [Accepted: 01/06/2019] [Indexed: 11/30/2022]
Abstract
IQGAP1 is a multifunctional, 190-kDa scaffolding protein that plays an important role in the regulation of cell adhesion, migration, proliferation, differentiation, polarization and cytoskeletal remodeling. IQGAP1 is ubiquitously expressed in human organs and is highly expressed in the kidney. Currently, the site-specific expression of IQGAP1 in the human nephrons is unclear. We performed Western blotting analysis, immunohistochemistry and double-immunolabeling confocal microscopic analysis of IQGAP1 with specific biomarkers of each nephron segment to study the expression and distribution of IQGAP1 in human nephrons. We found that IQGAP1 was strongly expressed in human podocytes and glomerular endothelial cells, but weakly expressed in glomerular mesangial cells. In human renal tubules, IQGAP1 was strongly expressed in the collecting duct, moderately expressed in the proximal tubule, medullary loop, distal convoluted tubule and connecting tubule. IQGAP1 staining was much stronger in the apical membrane in the proximal tubule, thick descending limb and thick ascending limb of medullary loop and collecting duct. However, the expression of IQGAP1 was mainly in the basolateral membrane of the connecting tubule, and diffusely in the thin limb of medullary loop and distal convoluted tubule. The interaction between IQGAP1 and F-actin suggested that cytoskeleton regulation may be the underlying mechanism mediating the effect of IQGAP1 in human nephrons. To the best of our knowledge, this is the first report of specific expression and differential subcellular location of IQGAP1 in human nephrons. The site-specific expression pattern of IQGAP1 suggests that IQGAP1 may play diverse roles in various human nephron segments.
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Affiliation(s)
- Ping Wang
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Xiaojie Gong
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Peizhong Guan
- Department of Nephrology, YEDA Hospital, Yantai, 264000, China
| | - Dong Ji
- Department of Dialysis, Huimin County People's Hospital, Binzhou, 251700, China
| | - Linna Du
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Dongmei Xu
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China
| | - Yipeng Liu
- Department of Nephrology, Shandong Provincial Qianfoshan Hospital, Shandong University, No.16766, Jingshi Road, Jinan, 250014, China.
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14
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Kruse R, Krantz J, Barker N, Coletta RL, Rafikov R, Luo M, Højlund K, Mandarino LJ, Langlais PR. Characterization of the CLASP2 Protein Interaction Network Identifies SOGA1 as a Microtubule-Associated Protein. Mol Cell Proteomics 2017; 16:1718-1735. [PMID: 28550165 DOI: 10.1074/mcp.ra117.000011] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Indexed: 12/26/2022] Open
Abstract
CLASP2 is a microtubule-associated protein that undergoes insulin-stimulated phosphorylation and co-localization with reorganized actin and GLUT4 at the plasma membrane. To gain insight to the role of CLASP2 in this system, we developed and successfully executed a streamlined interactome approach and built a CLASP2 protein network in 3T3-L1 adipocytes. Using two different commercially available antibodies for CLASP2 and an antibody for epitope-tagged, overexpressed CLASP2, we performed multiple affinity purification coupled with mass spectrometry (AP-MS) experiments in combination with label-free quantitative proteomics and analyzed the data with the bioinformatics tool Significance Analysis of Interactome (SAINT). We discovered that CLASP2 coimmunoprecipitates (co-IPs) the novel protein SOGA1, the microtubule-associated protein kinase MARK2, and the microtubule/actin-regulating protein G2L1. The GTPase-activating proteins AGAP1 and AGAP3 were also enriched in the CLASP2 interactome, although subsequent AGAP3 and CLIP2 interactome analysis suggests a preference of AGAP3 for CLIP2. Follow-up MARK2 interactome analysis confirmed reciprocal co-IP of CLASP2 and revealed MARK2 can co-IP SOGA1, glycogen synthase, and glycogenin. Investigating the SOGA1 interactome confirmed SOGA1 can reciprocal co-IP both CLASP2 and MARK2 as well as glycogen synthase and glycogenin. SOGA1 was confirmed to colocalize with CLASP2 and with tubulin, which identifies SOGA1 as a new microtubule-associated protein. These results introduce the metabolic function of these proposed novel protein networks and their relationship with microtubules as new fields of cytoskeleton-associated protein biology.
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Affiliation(s)
- Rikke Kruse
- From the ‡The Section of Molecular Diabetes & Metabolism, Department of Clinical Research and Institute of Molecular Medicine, University of Southern Denmark, DK-5000 Odense, Denmark.,§Department of Endocrinology, Odense University Hospital, DK-5000 Odense, Denmark
| | - James Krantz
- ¶Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona 85721
| | - Natalie Barker
- ¶Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona 85721
| | - Richard L Coletta
- ‖School of Life Sciences, Arizona State University, Tempe, Arizona 85787
| | - Ruslan Rafikov
- ¶Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona 85721
| | - Moulun Luo
- ¶Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona 85721
| | - Kurt Højlund
- From the ‡The Section of Molecular Diabetes & Metabolism, Department of Clinical Research and Institute of Molecular Medicine, University of Southern Denmark, DK-5000 Odense, Denmark.,§Department of Endocrinology, Odense University Hospital, DK-5000 Odense, Denmark
| | - Lawrence J Mandarino
- ¶Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona 85721
| | - Paul R Langlais
- ¶Department of Medicine, Division of Endocrinology, University of Arizona College of Medicine, Tucson, Arizona 85721;
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Zhu B, Qi L, Liu S, Liu W, Ou Z, Chen M, Liu L, Zu X, Wang J, Li Y. CLASP2 is involved in the EMT and early progression after transurethral resection of the bladder tumor. BMC Cancer 2017; 17:105. [PMID: 28166762 PMCID: PMC5294712 DOI: 10.1186/s12885-017-3101-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/01/2017] [Indexed: 01/17/2023] Open
Abstract
Background Cytoplasmic linker-associated protein 2 (CLASP2) belongs to a family of microtubule plus-end tracking proteins that localizes to the distal ends of microtubules and regulate microtubule dynamics. We speculated that it might be involved in the epithelial-mesenchymal transition (EMT) and progression of bladder cancer (BC). Methods Western blotting and RT-PCR were used to detect the changes at protein and mRNA levels in BC cell lines. Cell proliferation, clonogenic formation, wound healing and chamber invasion assay were used to investigate the abilities of cellular proliferation, migration and invasion. The data of BC patients treated with transurethral resection of the bladder tumor (TURBT) was collected and analyzed. The levels of mRNA of CLASP2 and EMT-related markers in tumor and urine samples were tested by RT-PCR. Results Expressions of CLASP2 varied in four BC cell lines. Manipulation of CLASP2 expression changed EMT-related markers. CLASP2 could promote proliferation, migration and invasion in BC cell lines. The combination (CLASP2 + E-cadherin mRNA in urine) could better discriminate the patients with or without 2-years progression compared with tumor grade after TURBT. Conclusion CLASP2 is involved in the EMT and progression of bladder urothelial cancer. Simultaneous urine-based detection of CLASP2 and E-cadherin mRNA can efficiently discriminate patients with or without 2-years progression after TURBT.
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Affiliation(s)
- Bisong Zhu
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China
| | - Lin Qi
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China
| | - Sulai Liu
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China
| | - Wentao Liu
- Department of Urology, The second Xiangya Hospital, Central South University, Renmin Road, Changsha, 410000, People's Republic of China
| | - Zhenyu Ou
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China
| | - Minfeng Chen
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China
| | - Longfei Liu
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China
| | - Xiongbing Zu
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China
| | - Jun Wang
- Department of Urology, The first affiliated Hospital, Zhengzhou University, No.1 Jianshe Dong Road, Zhengzhou, 450000, People's Republic of China
| | - Yuan Li
- Department of Urology, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Changsha, 410008, Hunan Province, People's Republic of China.
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Dema A, Schröter MF, Perets E, Skroblin P, Moutty MC, Deàk VA, Birchmeier W, Klussmann E. The A-Kinase Anchoring Protein (AKAP) Glycogen Synthase Kinase 3β Interaction Protein (GSKIP) Regulates β-Catenin through Its Interactions with Both Protein Kinase A (PKA) and GSK3β. J Biol Chem 2016; 291:19618-30. [PMID: 27484798 DOI: 10.1074/jbc.m116.738047] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Indexed: 01/24/2023] Open
Abstract
The A-kinase anchoring protein (AKAP) GSK3β interaction protein (GSKIP) is a cytosolic scaffolding protein binding protein kinase A (PKA) and glycogen synthase kinase 3β (GSK3β). Here we show that both the AKAP function of GSKIP, i.e. its direct interaction with PKA, and its direct interaction with GSK3β are required for the regulation of β-catenin and thus Wnt signaling. A cytoplasmic destruction complex targets β-catenin for degradation and thus prevents Wnt signaling. Wnt signals cause β-catenin accumulation and translocation into the nucleus, where it induces Wnt target gene expression. GSKIP facilitates control of the β-catenin stabilizing phosphorylation at Ser-675 by PKA. Its interaction with GSK3β facilitates control of the destabilizing phosphorylation of β-catenin at Ser-33/Ser-37/Thr-41. The influence of GSKIP on β-catenin is explained by its scavenger function; it recruits the kinases away from the destruction complex without forming a complex with β-catenin. The regulation of β-catenin by GSKIP is specific for this AKAP as AKAP220, which also binds PKA and GSK3β, did not affect Wnt signaling. We find that the binding domain of AKAP220 for GSK3β is a conserved GSK3β interaction domain (GID), which is also present in GSKIP. Our findings highlight an essential compartmentalization of both PKA and GSK3β by GSKIP, and ascribe a function to a cytosolic AKAP-PKA interaction as a regulatory factor in the control of canonical Wnt signaling. Wnt signaling controls different biological processes, including embryonic development, cell cycle progression, glycogen metabolism, and immune regulation; deregulation is associated with diseases such as cancer, type 2 diabetes, inflammatory, and Alzheimer's and Parkinson's diseases.
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Affiliation(s)
- Alessandro Dema
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and
| | - Micha Friedemann Schröter
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and
| | - Ekaterina Perets
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and
| | - Philipp Skroblin
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and
| | - Marie Christine Moutty
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and
| | - Veronika Anita Deàk
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and
| | - Walter Birchmeier
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and
| | - Enno Klussmann
- From the Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), Robert-Rössle-Strasse 10, 13125 Berlin, Germany and the DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Oudenarder Strasse 16, 13347 Berlin, Germany
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17
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AKAP220 manages apical actin networks that coordinate aquaporin-2 location and renal water reabsorption. Proc Natl Acad Sci U S A 2016; 113:E4328-37. [PMID: 27402760 DOI: 10.1073/pnas.1607745113] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Filtration through the kidney eliminates toxins, manages electrolyte balance, and controls water homeostasis. Reabsorption of water from the luminal fluid of the nephron occurs through aquaporin-2 (AQP2) water pores in principal cells that line the kidney-collecting duct. This vital process is impeded by formation of an "actin barrier" that obstructs the passive transit of AQP2 to the plasma membrane. Bidirectional control of AQP2 trafficking is managed by hormones and signaling enzymes. We have discovered that vasopressin-independent facets of this homeostatic mechanism are under the control of A-Kinase Anchoring Protein 220 (AKAP220; product of the Akap11 gene). CRISPR/Cas9 gene editing and imaging approaches show that loss of AKAP220 disrupts apical actin networks in organoid cultures. Similar defects are evident in tissue sections from AKAP220-KO mice. Biochemical analysis of AKAP220-null kidney extracts detected reduced levels of active RhoA GTPase, a well-known modulator of the actin cytoskeleton. Fluorescent imaging of kidney sections from these genetically modified mice revealed that RhoA and AQP2 accumulate at the apical surface of the collecting duct. Consequently, these animals are unable to appropriately dilute urine in response to overhydration. We propose that membrane-proximal signaling complexes constrained by AKAP220 impact the actin barrier dynamics and AQP2 trafficking to ensure water homeostasis.
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18
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Abstract
ERK1/2 MAP Kinases become activated in response to multiple intra- and extra-cellular stimuli through a signaling module composed of sequential tiers of cytoplasmic kinases. Scaffold proteins regulate ERK signals by connecting the different components of the module into a multi-enzymatic complex by which signal amplitude and duration are fine-tuned, and also provide signal fidelity by isolating this complex from external interferences. In addition, scaffold proteins play a central role as spatial regulators of ERKs signals. In this respect, depending on the subcellular localization from which the activating signals emanate, defined scaffolds specify which substrates are amenable to be phosphorylated. Recent evidence has unveiled direct interactions among different scaffold protein species. These scaffold-scaffold macro-complexes could constitute an additional level of regulation for ERK signals and may serve as nodes for the integration of incoming signals and the subsequent diversification of the outgoing signals with respect to substrate engagement.
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Affiliation(s)
- Berta Casar
- Instituto de Biomedicina y Biotecnología de Cantabria, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria Santander, Spain
| | - Piero Crespo
- Instituto de Biomedicina y Biotecnología de Cantabria, Consejo Superior de Investigaciones Científicas (CSIC) - Universidad de Cantabria Santander, Spain
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19
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Dema A, Perets E, Schulz MS, Deák VA, Klussmann E. Pharmacological targeting of AKAP-directed compartmentalized cAMP signalling. Cell Signal 2015; 27:2474-87. [PMID: 26386412 DOI: 10.1016/j.cellsig.2015.09.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/08/2015] [Accepted: 09/14/2015] [Indexed: 01/26/2023]
Abstract
The second messenger cyclic adenosine monophosphate (cAMP) can bind and activate protein kinase A (PKA). The cAMP/PKA system is ubiquitous and involved in a wide array of biological processes and therefore requires tight spatial and temporal regulation. Important components of the safeguard system are the A-kinase anchoring proteins (AKAPs), a heterogeneous family of scaffolding proteins defined by its ability to directly bind PKA. AKAPs tether PKA to specific subcellular compartments, and they bind further interaction partners to create local signalling hubs. The recent discovery of new AKAPs and advances in the field that shed light on the relevance of these hubs for human disease highlight unique opportunities for pharmacological modulation. This review exemplifies how interference with signalling, particularly cAMP signalling, at such hubs can reshape signalling responses and discusses how this could lead to novel pharmacological concepts for the treatment of disease with an unmet medical need such as cardiovascular disease and cancer.
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Affiliation(s)
- Alessandro Dema
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Ekaterina Perets
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Maike Svenja Schulz
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Veronika Anita Deák
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany; DZHK, German Centre for Cardiovascular Research, Oudenarder Straße 16, 13347 Berlin, Germany.
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20
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Whiting JL, Nygren PJ, Tunquist BJ, Langeberg LK, Seternes OM, Scott JD. Protein Kinase A Opposes the Phosphorylation-dependent Recruitment of Glycogen Synthase Kinase 3β to A-kinase Anchoring Protein 220. J Biol Chem 2015; 290:19445-57. [PMID: 26088133 DOI: 10.1074/jbc.m115.654822] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Indexed: 02/04/2023] Open
Abstract
The proximity of an enzyme to its substrate can influence rate and magnitude of catalysis. A-kinase anchoring protein 220 (AKAP220) is a multivalent anchoring protein that can sequester a variety of signal transduction enzymes. These include protein kinase A (PKA) and glycogen synthase kinase 3β (GSK3β). Using a combination of molecular and cellular approaches we show that GSK3β phosphorylation of Thr-1132 on AKAP220 initiates recruitment of this kinase into the enzyme scaffold. We also find that AKAP220 anchors GSK3β and its substrate β-catenin in membrane ruffles. Interestingly, GSK3β can be released from the multienzyme complex in response to PKA phosphorylation on serine 9, which suppresses GSK3β activity. The signaling scaffold may enhance this regulatory mechanism, as AKAP220 has the capacity to anchor two PKA holoenzymes. Site 1 on AKAP220 (residues 610-623) preferentially interacts with RII, whereas site 2 (residues 1633-1646) exhibits a dual specificity for RI and RII. In vitro affinity measurements revealed that site 2 on AKAP220 binds RII with ∼10-fold higher affinity than site 1. Occupancy of both R subunit binding sites on AKAP220 could provide a mechanism to amplify local cAMP responses and enable cross-talk between PKA and GSK3β.
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Affiliation(s)
- Jennifer L Whiting
- From the Howard Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Patrick J Nygren
- From the Howard Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Brian J Tunquist
- Translational Oncology, Array BioPharma, Inc., Boulder, Colorado 80301, and
| | - Lorene K Langeberg
- From the Howard Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Ole-Morten Seternes
- From the Howard Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195, Department of Pharmacy, University of Tromsø, The Arctic University of Norway, 9037 Tromsø, Norway
| | - John D Scott
- From the Howard Hughes Medical Institute, Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195,
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21
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Cooper DMF. Store-operated Ca²⁺-entry and adenylyl cyclase. Cell Calcium 2015; 58:368-75. [PMID: 25978874 DOI: 10.1016/j.ceca.2015.04.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Revised: 04/13/2015] [Accepted: 04/15/2015] [Indexed: 02/06/2023]
Abstract
One of the longest-standing effects of SOCE is in its selective regulation of Ca(2+)-sensitive adenylyl cyclase (AC) activity in non-excitable cells. Remarkably it was this source of Ca(2+) (SOCE) rather than the apparent magnitude of the Ca(2+)-rise that conferred AC responsiveness. The molecular basis for this dependence is now resolved in the case of adenylyl cyclase 8 (AC8). Sensors for Ca(2+) and cAMP targeted to ACs have been particularly useful in dissecting the influences upon and composition of what turn out to be signalling microdomains centred on ACs. A number of physiological processes depend on the regulation by SOCE of ACs, but the issue is under-studied. Here I will expand on these topics and point to some immediate unresolved questions.
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Affiliation(s)
- Dermot M F Cooper
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, United Kingdom.
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22
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Abel AM, Schuldt KM, Rajasekaran K, Hwang D, Riese MJ, Rao S, Thakar MS, Malarkannan S. IQGAP1: insights into the function of a molecular puppeteer. Mol Immunol 2015; 65:336-49. [PMID: 25733387 DOI: 10.1016/j.molimm.2015.02.012] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 02/09/2015] [Accepted: 02/09/2015] [Indexed: 02/06/2023]
Abstract
The intracellular spatiotemporal organization of signaling events is critical for normal cellular function. In response to environmental stimuli, cells utilize highly organized signaling pathways that are subject to multiple layers of regulation. However, the molecular mechanisms that coordinate these complex processes remain an enigma. Scaffolding proteins (scaffolins) have emerged as critical regulators of signaling pathways, many of which have well-described functions in immune cells. IQGAP1, a highly conserved cytoplasmic scaffold protein, is able to curb, compartmentalize, and coordinate multiple signaling pathways in a variety of cell types. IQGAP1 plays a central role in cell-cell interaction, cell adherence, and movement via actin/tubulin-based cytoskeletal reorganization. Evidence also implicates IQGAP1 as an essential regulator of the MAPK and Wnt/β-catenin signaling pathways. Here, we summarize the recent advances on the cellular and molecular biology of IQGAP1. We also describe how this pleiotropic scaffolin acts as a true molecular puppeteer, and highlight the significance of future research regarding the role of IQGAP1 in immune cells.
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Affiliation(s)
- Alex M Abel
- Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Microbiology & Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Kristina M Schuldt
- Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Kamalakannan Rajasekaran
- Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - David Hwang
- Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Matthew J Riese
- Department of Microbiology & Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Sridhar Rao
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Monica S Thakar
- Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Subramaniam Malarkannan
- Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Microbiology & Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Medicine, Medical College of Wisconsin, Milwaukee, WI 53226, USA; Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Hedman AC, Smith JM, Sacks DB. The biology of IQGAP proteins: beyond the cytoskeleton. EMBO Rep 2015; 16:427-46. [PMID: 25722290 DOI: 10.15252/embr.201439834] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/07/2015] [Indexed: 01/02/2023] Open
Abstract
IQGAP scaffold proteins are evolutionarily conserved in eukaryotes and facilitate the formation of complexes that regulate cytoskeletal dynamics, intracellular signaling, and intercellular interactions. Fungal and mammalian IQGAPs are implicated in cytokinesis. IQGAP1, IQGAP2, and IQGAP3 have diverse roles in vertebrate physiology, operating in the kidney, nervous system, cardio-vascular system, pancreas, and lung. The functions of IQGAPs can be corrupted during oncogenesis and are usurped by microbial pathogens. Therefore, IQGAPs represent intriguing candidates for novel therapeutic agents. While modulation of the cytoskeletal architecture was initially thought to be the primary function of IQGAPs, it is now clear that they have roles beyond the cytoskeleton. This review describes contributions of IQGAPs to physiology at the organism level.
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Affiliation(s)
- Andrew C Hedman
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Jessica M Smith
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
| | - David B Sacks
- Department of Laboratory Medicine, National Institutes of Health, Bethesda, MD, USA
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24
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IQGAPs choreograph cellular signaling from the membrane to the nucleus. Trends Cell Biol 2015; 25:171-84. [PMID: 25618329 DOI: 10.1016/j.tcb.2014.12.005] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 12/18/2022]
Abstract
Since its discovery in 1994, recognized cellular functions for the scaffold protein IQGAP1 have expanded immensely. Over 100 unique IQGAP1-interacting proteins have been identified, implicating IQGAP1 as a critical integrator of cellular signaling pathways. Initial research established functions for IQGAP1 in cell-cell adhesion, cell migration, and cell signaling. Recent studies have revealed additional IQGAP1 binding partners, expanding the biological roles of IQGAP1. These include crosstalk between signaling cascades, regulation of nuclear function, and Wnt pathway potentiation. Investigation of the IQGAP2 and IQGAP3 homologs demonstrates unique functions, some of which differ from those of IQGAP1. Summarized here are recent observations that enhance our understanding of IQGAP proteins in the integration of diverse signaling pathways.
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Poppinga WJ, Muñoz-Llancao P, González-Billault C, Schmidt M. A-kinase anchoring proteins: cAMP compartmentalization in neurodegenerative and obstructive pulmonary diseases. Br J Pharmacol 2014; 171:5603-23. [PMID: 25132049 PMCID: PMC4290705 DOI: 10.1111/bph.12882] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/14/2014] [Accepted: 08/10/2014] [Indexed: 12/25/2022] Open
Abstract
The universal second messenger cAMP is generated upon stimulation of Gs protein-coupled receptors, such as the β2 -adreneoceptor, and leads to the activation of PKA, the major cAMP effector protein. PKA oscillates between an on and off state and thereby regulates a plethora of distinct biological responses. The broad activation pattern of PKA and its contribution to several distinct cellular functions lead to the introduction of the concept of compartmentalization of cAMP. A-kinase anchoring proteins (AKAPs) are of central importance due to their unique ability to directly and/or indirectly interact with proteins that either determine the cellular content of cAMP, such as β2 -adrenoceptors, ACs and PDEs, or are regulated by cAMP such as the exchange protein directly activated by cAMP. We report on lessons learned from neurons indicating that maintenance of cAMP compartmentalization by AKAP5 is linked to neurotransmission, learning and memory. Disturbance of cAMP compartments seem to be linked to neurodegenerative disease including Alzheimer's disease. We translate this knowledge to compartmentalized cAMP signalling in the lung. Next to AKAP5, we focus here on AKAP12 and Ezrin (AKAP78). These topics will be highlighted in the context of the development of novel pharmacological interventions to tackle AKAP-dependent compartmentalization.
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Affiliation(s)
- W J Poppinga
- Department of Molecular Pharmacology, University of GroningenGroningen, The Netherlands
- Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of GroningenGroningen, The Netherlands
| | - P Muñoz-Llancao
- Department of Molecular Pharmacology, University of GroningenGroningen, The Netherlands
- Laboratory of Cell and Neuronal Dynamics (Cenedyn), Department of Biology, Faculty of Sciences, Universidad de ChileSantiago, Chile
- Department of Neuroscience, Section Medical Physiology, University Medical Center Groningen, University of GroningenGroningen, The Netherlands
| | - C González-Billault
- Laboratory of Cell and Neuronal Dynamics (Cenedyn), Department of Biology, Faculty of Sciences, Universidad de ChileSantiago, Chile
| | - M Schmidt
- Department of Molecular Pharmacology, University of GroningenGroningen, The Netherlands
- Groningen Research Institute for Asthma and COPD (GRIAC), University Medical Center Groningen, University of GroningenGroningen, The Netherlands
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26
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Abstract
Recent advances in the AC (adenylate cyclase)/cAMP field reveal overarching roles for the ACs. Whereas few processes are unaffected by cAMP in eukaryotes, ranging from the rapid modulation of ion channel kinetics to the slowest developmental effects, the large number of cellular processes modulated by only three intermediaries, i.e. PKA (protein kinase A), Epacs (exchange proteins directly activated by cAMP) and CNG (cyclic nucleotide-gated) channels, poses the question of how selectivity and fine control is achieved by cAMP. One answer rests on the number of differently regulated and distinctly expressed AC species. Specific ACs are implicated in processes such as insulin secretion, immunological responses, sino-atrial node pulsatility and memory formation, and specific ACs are linked with particular diseased conditions or predispositions, such as cystic fibrosis, Type 2 diabetes and dysrhythmias. However, much of the selectivity and control exerted by cAMP lies in the sophisticated properties of individual ACs, in terms of their coincident responsiveness, dynamic protein scaffolding and organization of cellular microassemblies. The ACs appear to be the centre of highly organized microdomains, where both cAMP and Ca2+, the other major influence on ACs, change in patterns quite discrete from the broad cellular milieu. How these microdomains are organized is beginning to become clear, so that ACs may now be viewed as fundamental signalling centres, whose properties exceed their production of cAMP. In the present review, we summarize how ACs are multiply regulated and the steps that are put in place to ensure discrimination in their signalling. This includes scaffolding of targets and modulators by the ACs and assembling of signalling nexuses in discrete cellular domains. We also stress how these assemblies are cell-specific, context-specific and dynamic, and may be best addressed by targeted biosensors. These perspectives on the organization of ACs uncover new strategies for intervention in systems mediated by cAMP, which promise far more informed specificity than traditional approaches.
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Siesser PF, Motolese M, Walker MP, Goldfarb D, Gewain K, Yan F, Kulikauskas RM, Chien AJ, Wordeman L, Major MB. FAM123A binds to microtubules and inhibits the guanine nucleotide exchange factor ARHGEF2 to decrease actomyosin contractility. Sci Signal 2012; 5:ra64. [PMID: 22949735 DOI: 10.1126/scisignal.2002871] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The FAM123 gene family comprises three members: FAM123A, the tumor suppressor WTX (also known as FAM123B), and FAM123C. WTX is required for normal development and causally contributes to human disease, in part through its regulation of β-catenin-dependent WNT signaling. The roles of FAM123A and FAM123C in signaling, cell behavior, and human disease remain less understood. We defined and compared the protein-protein interaction networks for each member of the FAM123 family by affinity purification and mass spectrometry. Protein localization and functional studies suggest that the FAM123 family members have conserved and divergent cellular roles. In contrast to WTX and FAM123C, we found that microtubule-associated proteins were enriched in the FAM123A protein interaction network. FAM123A interacted with and tracked with the plus end of dynamic microtubules. Domain interaction experiments revealed a "SKIP" amino acid motif in FAM123A that mediated interaction with the microtubule tip tracking proteins end-binding protein 1 (EB1) and EB3--and therefore with microtubules. Cells depleted of FAM123A showed compartment-specific effects on microtubule dynamics, increased actomyosin contractility, larger focal adhesions, and decreased cell migration. These effects required binding of FAM123A to and inhibition of the guanine nucleotide exchange factor ARHGEF2, a microtubule-associated activator of RhoA. Together, these data suggest that the SKIP motif enables FAM123A, but not the other FAM123 family members, to bind to EB proteins, localize to microtubules, and coordinate microtubule dynamics and actomyosin contractility.
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Affiliation(s)
- Priscila F Siesser
- Department of Cell and Developmental Biology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
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Stumpff J, Wagenbach M, Franck A, Asbury CL, Wordeman L. Kif18A and chromokinesins confine centromere movements via microtubule growth suppression and spatial control of kinetochore tension. Dev Cell 2012; 22:1017-29. [PMID: 22595673 DOI: 10.1016/j.devcel.2012.02.013] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 12/08/2011] [Accepted: 02/28/2012] [Indexed: 10/28/2022]
Abstract
Alignment of chromosomes at the metaphase plate is a signature of cell division in metazoan cells, yet the mechanisms controlling this process remain ambiguous. Here we use a combination of quantitative live-cell imaging and reconstituted dynamic microtubule assays to investigate the molecular control of mitotic centromere movements. We establish that Kif18A (kinesin-8) attenuates centromere movement by directly promoting microtubule pausing in a concentration-dependent manner. This activity provides the dominant mechanism for restricting centromere movement to the spindle midzone. Furthermore, polar ejection forces spatially confine chromosomes via position-dependent regulation of kinetochore tension and centromere switch rates. We demonstrate that polar ejection forces are antagonistically modulated by chromokinesins. These pushing forces depend on Kid (kinesin-10) activity and are antagonized by Kif4A (kinesin-4), which functions to directly suppress microtubule growth. These data support a model in which Kif18A and polar ejection forces synergistically promote centromere alignment via spatial control of kinetochore-microtubule dynamics.
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Affiliation(s)
- Jason Stumpff
- Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195, USA.
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29
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Malarkannan S, Awasthi A, Rajasekaran K, Kumar P, Schuldt KM, Bartoszek A, Manoharan N, Goldner NK, Umhoefer CM, Thakar MS. IQGAP1: a regulator of intracellular spacetime relativity. THE JOURNAL OF IMMUNOLOGY 2012; 188:2057-63. [PMID: 22345702 DOI: 10.4049/jimmunol.1102439] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Activating and inhibiting receptors of lymphocytes collect valuable information about their mikròs kósmos. This information is essential to initiate or to turn off complex signaling pathways. Irrespective of these advances, our knowledge on how these intracellular activation cascades are coordinated in a spatiotemporal manner is far from complete. Among multiple explanations, the scaffolding proteins have emerged as a critical piece of this evolutionary tangram. Among many, IQGAP1 is one of the essential scaffolding proteins that coordinate multiple signaling pathways. IQGAP1 possesses multiple protein interaction motifs to achieve its scaffolding functions. Using these domains, IQGAP1 has been shown to regulate a number of essential cellular events. This includes actin polymerization, tubulin multimerization, microtubule organizing center formation, calcium/calmodulin signaling, Pak/Raf/Mek1/2-mediated Erk1/2 activation, formation of maestrosome, E-cadherin, and CD44-mediated signaling and glycogen synthase kinase-3/adenomatous polyposis coli-mediated β-catenin activation. In this review, we summarize the recent developments and exciting new findings of cellular functions of IQGAP1.
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Affiliation(s)
- Subramaniam Malarkannan
- Laboratory of Molecular Immunology and Immunotherapy, Blood Research Institute, Milwaukee, WI 53226, USA.
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30
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Dráber P, Sulimenko V, Dráberová E. Cytoskeleton in mast cell signaling. Front Immunol 2012; 3:130. [PMID: 22654883 PMCID: PMC3360219 DOI: 10.3389/fimmu.2012.00130] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 05/05/2012] [Indexed: 11/13/2022] Open
Abstract
Mast cell activation mediated by the high affinity receptor for IgE (FcεRI) is a key event in allergic response and inflammation. Other receptors on mast cells, as c-Kit for stem cell factor and G protein-coupled receptors (GPCRs) synergistically enhance the FcεRI-mediated release of inflammatory mediators. Activation of various signaling pathways in mast cells results in changes in cell morphology, adhesion to substrate, exocytosis, and migration. Reorganization of cytoskeleton is pivotal in all these processes. Cytoskeletal proteins also play an important role in initial stages of FcεRI and other surface receptors induced triggering. Highly dynamic microtubules formed by αβ-tubulin dimers as well as microfilaments build up from polymerized actin are affected in activated cells by kinases/phosphatases, Rho GTPases and changes in concentration of cytosolic Ca(2+). Also important are nucleation proteins; the γ-tubulin complexes in case of microtubules or Arp 2/3 complex with its nucleation promoting factors and formins in case of microfilaments. The dynamic nature of microtubules and microfilaments in activated cells depends on many associated/regulatory proteins. Changes in rigidity of activated mast cells reflect changes in intermediate filaments build up from vimentin. This review offers a critical appraisal of current knowledge on the role of cytoskeleton in mast cells signaling.
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Affiliation(s)
- Pavel Dráber
- Department of Biology of Cytoskeleton, Institute of Molecular Genetics, Academy of Sciences of the Czech RepublicPrague, Czech Republic
| | - Vadym Sulimenko
- Department of Biology of Cytoskeleton, Institute of Molecular Genetics, Academy of Sciences of the Czech RepublicPrague, Czech Republic
| | - Eduarda Dráberová
- Department of Biology of Cytoskeleton, Institute of Molecular Genetics, Academy of Sciences of the Czech RepublicPrague, Czech Republic
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31
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White CD, Erdemir HH, Sacks DB. IQGAP1 and its binding proteins control diverse biological functions. Cell Signal 2011; 24:826-34. [PMID: 22182509 DOI: 10.1016/j.cellsig.2011.12.005] [Citation(s) in RCA: 171] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 12/04/2011] [Indexed: 12/26/2022]
Abstract
IQGAP proteins have been identified in a wide spectrum of organisms, ranging from yeast to humans. The most extensively studied family member is the ubiquitously expressed scaffold protein IQGAP1, which participates in multiple essential aspects of mammalian biology. IQGAP1 mediates these effects by binding to and regulating the function of numerous interacting proteins. Over ninety proteins have been reported to associate with IQGAP1, either directly or as part of a larger complex. In this review, we summarise those IQGAP1 binding partners that have been identified in the last five years. The molecular mechanisms by which these interactions contribute to the functions of receptors and their signalling cascades, small GTPase function, cytoskeletal dynamics, neuronal regulation and intracellular trafficking are evaluated. The evidence that has accumulated recently validates the role of IQGAP1 as a scaffold protein and expands the repertoire of cellular activities in which it participates.
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Affiliation(s)
- Colin D White
- Department of Pathology, Beth Israel Deaconess Medical Centre and Harvard Medical School, 3 Blackfan Circle, Boston, MA 02115, USA
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