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Öster L, Castaldo M, de Vries E, Edfeldt F, Pemberton N, Gordon E, Cederblad L, Käck H. The structures of salt-inducible kinase 3 in complex with inhibitors reveal determinants for binding and selectivity. J Biol Chem 2024; 300:107201. [PMID: 38508313 PMCID: PMC11061224 DOI: 10.1016/j.jbc.2024.107201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 03/11/2024] [Accepted: 03/14/2024] [Indexed: 03/22/2024] Open
Abstract
The salt-inducible kinases (SIKs) 1 to 3, belonging to the AMPK-related kinase family, serve as master regulators orchestrating a diverse set of physiological processes such as metabolism, bone formation, immune response, oncogenesis, and cardiac rhythm. Owing to its key regulatory role, the SIK kinases have emerged as compelling targets for pharmacological intervention across a diverse set of indications. Therefore, there is interest in developing SIK inhibitors with defined selectivity profiles both to further dissect the downstream biology and for treating disease. However, despite a large pharmaceutical interest in the SIKs, experimental structures of SIK kinases are scarce. This is likely due to the challenges associated with the generation of proteins suitable for structural studies. By adopting a rational approach to construct design and protein purification, we successfully crystallized and subsequently solved the structure of SIK3 in complex with HG-9-91-01, a potent SIK inhibitor. To enable further SIK3-inhibitor complex structures we identified an antibody fragment that facilitated crystallization and enabled a robust protocol suitable for structure-based drug design. The structures reveal SIK3 in an active conformation, where the ubiquitin-associated domain is shown to provide further stabilization to this active conformation. We present four pharmacologically relevant and distinct SIK3-inhibitor complexes. These detail the key interaction for each ligand and reveal how different regions of the ATP site are engaged by the different inhibitors to achieve high affinity. Notably, the structure of SIK3 in complex with a SIK3 specific inhibitor offers insights into isoform selectivity.
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Affiliation(s)
- Linda Öster
- Mechanistic and Structural Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden.
| | - Marie Castaldo
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Emma de Vries
- Biologics Engineering, R&D, AstraZeneca, Cambridge, UK
| | - Fredrik Edfeldt
- Mechanistic and Structural Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Nils Pemberton
- Medicinal Chemistry, Research & Early Development, Respiratory & Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Euan Gordon
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Linda Cederblad
- Discovery Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden
| | - Helena Käck
- Mechanistic and Structural Biology, Discovery Sciences, R&D, AstraZeneca, Gothenburg, Sweden.
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2
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Yang J, Niu H, Pang S, Liu M, Chen F, Li Z, He L, Mo J, Yi H, Xiao J, Huang Y. MARK3 kinase: Regulation and physiologic roles. Cell Signal 2023; 103:110578. [PMID: 36581219 DOI: 10.1016/j.cellsig.2022.110578] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/14/2022] [Accepted: 12/20/2022] [Indexed: 12/27/2022]
Abstract
Microtubule affinity-regulating kinase 3 (MARK3), a member of the MARK family, regulates several essential pathways, including the cell cycle, ciliated cell differentiation, and osteoclast differentiation. It is important to understand the control of their activities as MARK3 contains an N-terminal serine/threonine kinase domain, ubiquitin-associated domain, and C-terminal kinase-associated domain, which perform multiple regulatory functions. These functions include post-translational modification (e.g., phosphorylation) and interaction with scaffolding and other proteins. Differences in the amino acid sequence and domain position result in different three-dimensional protein structures and affect the function of MARK3, which distinguish it from the other MARK family members. Recent data indicate a potential role of MARK3 in several pathological conditions, including congenital blepharophimosis syndrome, osteoporosis, and tumorigenesis. The present review focuses on the physiological and pathological role of MARK3, its regulation, and recent developments in the small molecule inhibitors of the MARK3 signalling cascade.
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Affiliation(s)
- Jingyu Yang
- Surgery of Mammary Gland and Thyroid Gland, the First People's Hospital of Yunnan Province, Panlong Campus, 157 Jinbi Road, Kunming 650032, Yunnan, People's Republic of China
| | - Heng Niu
- Surgery of Mammary Gland and Thyroid Gland, the First People's Hospital of Yunnan Province, Panlong Campus, 157 Jinbi Road, Kunming 650032, Yunnan, People's Republic of China
| | - ShiGui Pang
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Mignlong Liu
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Feng Chen
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Zhaoxin Li
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Lifei He
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Jianmei Mo
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Huijun Yi
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Juanjuan Xiao
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China
| | - Yingze Huang
- Cancer Research Institute, The Affiliated Hospital of Guilin Medical University, Xiufeng Campus, 15 Lequn Road, Guilin 541001, Guangxi, People's Republic of China.
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3
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Mingione VR, Paung Y, Outhwaite IR, Seeliger MA. Allosteric regulation and inhibition of protein kinases. Biochem Soc Trans 2023; 51:373-385. [PMID: 36794774 PMCID: PMC10089111 DOI: 10.1042/bst20220940] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/31/2023] [Accepted: 02/01/2023] [Indexed: 02/17/2023]
Abstract
The human genome encodes more than 500 different protein kinases: signaling enzymes with tightly regulated activity. Enzymatic activity within the conserved kinase domain is influenced by numerous regulatory inputs including the binding of regulatory domains, substrates, and the effect of post-translational modifications such as autophosphorylation. Integration of these diverse inputs occurs via allosteric sites that relate signals via networks of amino acid residues to the active site and ensures controlled phosphorylation of kinase substrates. Here, we review mechanisms of allosteric regulation of protein kinases and recent advances in the field.
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Affiliation(s)
- Victoria R. Mingione
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - YiTing Paung
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ian R. Outhwaite
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Markus A. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
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4
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Shi M, Zhou Y, Wei H, Zhang X, Du M, Zhou Y, Yin Y, Li X, Tang X, Sun L, Xu D, Li X. Interactions between curcumin and human salt-induced kinase 3 elucidated from computational tools and experimental methods. Front Pharmacol 2023; 14:1116098. [PMID: 37124223 PMCID: PMC10133576 DOI: 10.3389/fphar.2023.1116098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 04/03/2023] [Indexed: 05/02/2023] Open
Abstract
Natural products are widely used for treating mitochondrial dysfunction-related diseases and cancers. Curcumin, a well-known natural product, can be potentially used to treat cancer. Human salt-induced kinase 3 (SIK3) is one of the target proteins for curcumin. However, the interactions between curcumin and human SIK3 have not yet been investigated in detail. In this study, we studied the binding models for the interactions between curcumin and human SIK3 using computational tools such as homology modeling, molecular docking, molecular dynamics simulations, and binding free energy calculations. The open activity loop conformation of SIK3 with the ketoenol form of curcumin was the optimal binding model. The I72, V80, A93, Y144, A145, and L195 residues played a key role for curcumin binding with human SIK3. The interactions between curcumin and human SIK3 were also investigated using the kinase assay. Moreover, curcumin exhibited an IC50 (half-maximal inhibitory concentration) value of 131 nM, and it showed significant antiproliferative activities of 9.62 ± 0.33 µM and 72.37 ± 0.37 µM against the MCF-7 and MDA-MB-23 cell lines, respectively. This study provides detailed information on the binding of curcumin with human SIK3 and may facilitate the design of novel salt-inducible kinases inhibitors.
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Affiliation(s)
- Mingsong Shi
- NHC Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, Sichuan, China
| | - Yan Zhou
- NHC Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, Sichuan, China
| | - Haoche Wei
- State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xinyu Zhang
- West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Meng Du
- College of Chemistry, MOE Key Laboratory of Green Chemistry and Technology, Sichuan University, Chengdu, Sichuan, China
| | - Yanting Zhou
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnocentric of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China
| | - Yuan Yin
- NHC Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, Sichuan, China
| | - Xinghui Li
- West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Xinyi Tang
- West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, China
| | - Liang Sun
- Shenzhen Shuli Tech Co., Ltd, Shenzhen, Guangdong, China
| | - Dingguo Xu
- College of Chemistry, MOE Key Laboratory of Green Chemistry and Technology, Sichuan University, Chengdu, Sichuan, China
- Research Center for Material Genome Engineering, Sichuan University, Chengdu, Sichuan, China
- *Correspondence: Dingguo Xu, ; Xiaoan Li,
| | - Xiaoan Li
- NHC Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, Sichuan, China
- *Correspondence: Dingguo Xu, ; Xiaoan Li,
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Nishikawa H, Christiany P, Hayashi T, Iizasa H, Yoshiyama H, Hatakeyama M. Kinase Activity of PAR1b, Which Mediates Nuclear Translocation of the BRCA1 Tumor Suppressor, Is Potentiated by Nucleic Acid-Mediated PAR1b Multimerization. Int J Mol Sci 2022; 23:6634. [PMID: 35743080 PMCID: PMC9223676 DOI: 10.3390/ijms23126634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/09/2022] [Accepted: 06/12/2022] [Indexed: 02/07/2023] Open
Abstract
PAR1b is a cytoplasmic serine/threonine kinase that controls cell polarity and cell-cell interaction by regulating microtubule stability while mediating cytoplasmic-to-nuclear translocation of BRCA1. PAR1b is also a cellular target of the CagA protein of Helicobacter pylori, which leads to chronic infection causatively associated with the development of gastric cancer. The CagA-PAR1b interaction inactivates the kinase activity of PAR1b and thereby dampens PAR1b-mediated BRCA1 phosphorylation, which reduces the level of nuclear BRCA1 and thereby leads to BRCAness and BRCAness-associated genome instability underlying gastric carcinogenesis. While PAR1b can multimerize within the cells, little is known about the mechanism and functional role of PAR1b multimerization. We found in the present study that PAR1b was multimerized in vitro by binding with nucleic acids (both single- and double-stranded DNA/RNA) via the spacer region in a manner independent of nucleic-acid sequences, which markedly potentiated the kinase activity of PAR1b. Consistent with these in vitro observations, cytoplasmic introduction of double-stranded DNA or expression of single-stranded RNA increased the PAR1b kinase activity in the cells. These findings indicate that the cytoplasmic DNA/RNA contribute to nuclear accumulation of BRCA1 by constitutively activating/potentiating cytoplasmic PAR1b kinase activity, which is subverted in gastric epithelial cells upon delivery of H. pylori CagA oncoprotein.
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Affiliation(s)
- Hiroko Nishikawa
- Division of Microbiology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; (H.N.); (P.C.); (T.H.)
| | - Priscillia Christiany
- Division of Microbiology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; (H.N.); (P.C.); (T.H.)
| | - Takeru Hayashi
- Division of Microbiology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; (H.N.); (P.C.); (T.H.)
| | - Hisashi Iizasa
- Department of Microbiology, Faculty of Medicine, Shimane University, Izumo 693-8501, Japan; (H.I.); (H.Y.)
| | - Hironori Yoshiyama
- Department of Microbiology, Faculty of Medicine, Shimane University, Izumo 693-8501, Japan; (H.I.); (H.Y.)
| | - Masanori Hatakeyama
- Division of Microbiology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan; (H.N.); (P.C.); (T.H.)
- Laboratory of Virology, Institute of Microbial Chemistry, Microbial Chemistry Research Foundation, Shinagawa-ku, Tokyo 141-0021, Japan
- Center for Infectious Cancers, Institute for Genetic Medicine, Hokkaido University, Kita-ku, Sapporo 060-0815, Japan
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6
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Shi M, Wang L, Liu K, Chen Y, Hu M, Yang L, He J, Chen L, Xu D. Molecular Dynamics Simulations of the Conformational Plasticity in the Active Pocket of Salt-Inducible Kinase 2 (SIK2) Multi-State Binding with Bosutinib. Comput Struct Biotechnol J 2022; 20:2574-2586. [PMID: 35685353 PMCID: PMC9160496 DOI: 10.1016/j.csbj.2022.05.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 11/06/2022] Open
Abstract
The kinase domain is highly conserved among protein kinases 'in terms of both sequence and structure. Conformational rearrangements of the kinase domain are affected by the phosphorylation of residues and the binding of kinase inhibitors. Interestingly, the conformational rearrangement of the active pocket plays an important role in kinase activity and can be used to design novel kinase inhibitors. We characterized the conformational plasticity of the active pocket when bosutinib was bound to salt-inducible kinase 2 (SIK2) using homology modeling and molecular dynamics simulations. Ten different initial complex models were constructed using the Morph server, ranging from open to closed conformations of SIK2 binding with bosutinib. Our simulation showed that bosutinib binds SIK2 with up or down conformations of the P-loop and with all the conformations of the activation loop. In addition, the αC-helix conformation was induced by the conformation of the activation loop, and the salt bridge formed only with its open conformation. The binding affinity of the models was also determined using the molecular mechanics generalized Born surface area method. Bosutinib was found to form a strong binding model with SIK2 and hydrophobic interactions were the dominant factor. This discovery may help guide the design of novel SIK2 inhibitors.
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7
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Day M, Parry-Morris S, Houghton-Gisby J, Oliver AW, Pearl LH. Structural basis for recruitment of the CHK1 DNA damage kinase by the CLASPIN scaffold protein. Structure 2021; 29:531-539.e3. [PMID: 33789090 PMCID: PMC8204404 DOI: 10.1016/j.str.2021.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/11/2021] [Accepted: 03/10/2021] [Indexed: 01/08/2023]
Abstract
CHK1 is a protein kinase that functions downstream of activated ATR to phosphorylate multiple targets as part of intra-S and G2/M DNA damage checkpoints. Its role in allowing cells to survive replicative stress has made it an important target for anti-cancer drug discovery. Activation of CHK1 by ATR depends on their mutual interaction with CLASPIN, a natively unstructured protein that interacts with CHK1 through a cluster of phosphorylation sites in its C-terminal half. We have now determined the crystal structure of the kinase domain of CHK1 bound to a high-affinity motif from CLASPIN. Our data show that CLASPIN engages a conserved site on CHK1 adjacent to the substrate-binding cleft, involved in phosphate sensing in other kinases. The CLASPIN motif is not phosphorylated by CHK1, nor does it affect phosphorylation of a CDC25 substrate peptide, suggesting that it functions purely as a scaffold for CHK1 activation by ATR. Novel crystal forms of the CHK1 kinase domain are reported Nucleotide-bound CHK1 structure Phosphorylated CLASPIN peptide-bound CHK1 structure CHK1-CLASPIN interaction does not affect kinase kinetics
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Affiliation(s)
- Matthew Day
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Sarah Parry-Morris
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Jack Houghton-Gisby
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK
| | - Antony W Oliver
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
| | - Laurence H Pearl
- Cancer Research UK DNA Repair Enzymes Group, Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9RQ, UK.
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Jasani A, Huynh T, Kellogg DR. Growth-Dependent Activation of Protein Kinases Suggests a Mechanism for Measuring Cell Growth. Genetics 2020; 215:729-46. [PMID: 32461268 DOI: 10.1534/genetics.120.303200] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/17/2020] [Indexed: 11/18/2022] Open
Abstract
In all cells, progression through the cell cycle occurs only when sufficient growth has occurred. Thus, cells must translate growth into a proportional signal that can be used to measure and transmit information about growth. Previous genetic studies in budding yeast suggested that related kinases called Gin4 and Hsl1 could function in mechanisms that measure bud growth; however, interpretation of the data was complicated by the use of gene deletions that cause complex terminal phenotypes. Here, we used the first conditional alleles of Gin4 and Hsl1 to more precisely define their functions. We show that excessive bud growth during a prolonged mitotic delay is an immediate consequence of inactivating Gin4 and Hsl1 Thus, acute loss of Gin4 and Hsl1 causes cells to behave as though they cannot detect that bud growth has occurred. We further show that Gin4 and Hsl1 undergo gradual hyperphosphorylation during bud growth that is dependent upon growth and correlated with the extent of growth. Moreover, gradual hyperphosphorylation of Gin4 during bud growth requires binding to anionic phospholipids that are delivered to the growing bud. While alternative models are possible, the data suggest that signaling lipids delivered to the growing bud generate a growth-dependent signal that could be used to measure bud growth.
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Sonntag T, Moresco JJ, Yates JR, Montminy M. The KLDpT activation loop motif is critical for MARK kinase activity. PLoS One 2019; 14:e0225727. [PMID: 31794565 PMCID: PMC6890249 DOI: 10.1371/journal.pone.0225727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 11/11/2019] [Indexed: 11/19/2022] Open
Abstract
MAP/microtubule-affinity regulating kinases (MARK1-4) are members of the AMPK family of Ser/Thr-specific kinases, which phosphorylate substrates at consensus LXRXXSXXXL motifs. Within microtubule-associated proteins, MARKs also mediate phosphorylation of variant KXGS or ζXKXGSXXNΨ motifs, interfering with the ability of tau and MAP2/4 to bind to microtubules. Here we show that, although MARKs and the closely related salt-inducible kinases (SIKs) phosphorylate substrates with consensus AMPK motifs comparably, MARKs are more potent in recognizing variant ζXKXGSXXNΨ motifs on cellular tau. In studies to identify regions of MARKs that confer catalytic activity towards variant sites, we found that the C-terminal kinase associated-1 (KA1) domain in MARK1-3 mediates binding to microtubule-associated proteins CLASP1/2; but this interaction is dispensable for ζXKXGSXXNΨ phosphorylation. Mutational analysis of MARK2 revealed that the N-terminal kinase domain of MARK2 is sufficient for phosphorylation of both consensus and variant ζXKXGSXXNΨ sites. Within this domain, the KLDpT activation loop motif promotes MARK2 activity both intracellularly and in vitro, but has no effect on SIK2 activity. As KLDpT is conserved in all vertebrates MARKs, we conclude that this sequence is crucial for MARK-dependent regulation of cellular polarity.
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Affiliation(s)
- Tim Sonntag
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - James J. Moresco
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - John R. Yates
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States of America
| | - Marc Montminy
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, La Jolla, California, United States of America
- * E-mail:
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10
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Abstract
The enzymatic activity of protein kinases is often tightly controlled by regulatory domains with a conserved structural mechanism. In this issue of Structure, Emptage et al. (2018) report how the kinase associated-1 domain (KA1) autoinhibits kinase activity with a striking structural diversity.
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Affiliation(s)
- YiTing Paung
- Department of Pharmacological Sciences, Stony Brook University, School of Medicine, BST 8-140, Stony Brook, NY 11794, USA
| | - Markus A Seeliger
- Department of Pharmacological Sciences, Stony Brook University, School of Medicine, BST 8-140, Stony Brook, NY 11794, USA.
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11
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Abstract
The MARK/PAR-1 family of kinases are conserved regulators of cell polarity that share a conserved C-terminal kinase-associated domain (KA1). Localization of MARK/PAR-1 kinases to specific regions of the cell cortex is a hallmark of polarized cells. In Caenorhabditiselegans zygotes, PAR-1 localizes to the posterior cortex under the influence of another polarity kinase, aPKC/PKC-3. Here, we report that asymmetric localization of PAR-1 protein is not essential, and that PAR-1 kinase activity is regulated spatially. We find that, as in human MARK1, the PAR-1 KA1 domain is an auto-inhibitory domain that suppresses kinase activity. Auto-inhibition by the KA1 domain functions in parallel with phosphorylation by PKC-3 to suppress PAR-1 activity in the anterior cytoplasm. The KA1 domain also plays an additional role that is essential for germ plasm maintenance and fertility. Our findings suggest that modular regulation of kinase activity by redundant inhibitory inputs contributes to robust symmetry breaking by MARK/PAR-1 kinases in diverse cell types.
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Affiliation(s)
- Andrew W Folkmann
- Department of Molecular Biology and Genetics, HHMI, Johns Hopkins University, School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Geraldine Seydoux
- Department of Molecular Biology and Genetics, HHMI, Johns Hopkins University, School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
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