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Fitz GN, Tyska MJ. Molecular counting of myosin force generators in growing filopodia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.593924. [PMID: 38798618 PMCID: PMC11118519 DOI: 10.1101/2024.05.14.593924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Animal cells build actin-based surface protrusions to enable biological activities ranging from cell motility to mechanosensation to solute uptake. Long-standing models of protrusion growth suggest that actin filament polymerization provides the primary mechanical force for "pushing" the plasma membrane outward at the distal tip. Expanding on these actin-centric models, our recent studies used a chemically inducible system to establish that plasma membrane-bound myosin motors, which are abundant in protrusions and accumulate at the distal tips, can also power robust filopodial growth. How protrusion resident myosins coordinate with actin polymerization to drive elongation remains unclear, in part because the number of force generators and thus, the scale of their mechanical contributions remain undefined. To address this gap, we leveraged the SunTag system to count membrane-bound myosin motors in actively growing filopodia. Using this approach, we found that the number of myosins is log-normally distributed with a mean of 12.0 ± 2.5 motors [GeoMean ± GeoSD] per filopodium. Together with unitary force values and duty ratio estimates derived from biophysical studies for the motor used in these experiments, we calculate that a distal tip population of myosins could generate a time averaged force of ∼tens of pN to elongate filopodia. This range is comparable to the expected force production of actin polymerization in this system, a point that necessitates revision of popular physical models for protrusion growth. SIGNIFICANCE STATEMENT This study describes the results of in-cell molecular counting experiments to define the number of myosin motors that are mechanically active in growing filopodia. This data should be used to constrain future physical models of the formation of actin-based protrusions.
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2
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Ebrahimi AM, Gawlik W, Wojciechowski AM, Rajfur Z. Cell-particles interaction - selective uptake and transport of microdiamonds. Commun Biol 2024; 7:318. [PMID: 38480800 PMCID: PMC10937934 DOI: 10.1038/s42003-024-05974-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 02/26/2024] [Indexed: 03/17/2024] Open
Abstract
Diamond particles have recently emerged as novel agents in cellular studies because of their superb biocompatibility. Their unique characteristics, including small size and the presence of fluorescent color centers, stimulate many important applications. However, the mechanism of interaction between cells and diamond particles-uptake, transport, and final localization within cells-is not yet fully understood. Herein, we show a novel, to the best of our knowledge, cell behavior wherein cells actively target and uptake diamond particles rather than latex beads from their surroundings, followed by their active transport within cells. Furthermore, we demonstrate that myosin-X is involved in cell-particle interaction, while myosin-II does not participate in particle uptake and transport. These results can have important implications for drug delivery and improve sensing methods that use diamond particles.
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Affiliation(s)
- Armin M Ebrahimi
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348, Kraków, Poland
- Doctoral School of Exact and Natural Sciences, Jagiellonian University, 30-348, Kraków, Poland
| | - Wojciech Gawlik
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348, Kraków, Poland
| | - Adam M Wojciechowski
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348, Kraków, Poland.
| | - Zenon Rajfur
- Marian Smoluchowski Institute of Physics, Jagiellonian University, 30-348, Kraków, Poland.
- Jagiellonian Center of Biomedical Imaging, Jagiellonian University, 30-348, Kraków, Poland.
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3
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Popović A, Miihkinen M, Ghimire S, Saup R, Grönloh MLB, Ball NJ, Goult BT, Ivaska J, Jacquemet G. Myosin-X recruits lamellipodin to filopodia tips. J Cell Sci 2023; 136:293507. [PMID: 36861887 PMCID: PMC10022686 DOI: 10.1242/jcs.260574] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 01/12/2023] [Indexed: 03/03/2023] Open
Abstract
Myosin-X (MYO10), a molecular motor localizing to filopodia, is thought to transport various cargo to filopodia tips, modulating filopodia function. However, only a few MYO10 cargoes have been described. Here, using GFP-Trap and BioID approaches combined with mass spectrometry, we identified lamellipodin (RAPH1) as a novel MYO10 cargo. We report that the FERM domain of MYO10 is required for RAPH1 localization and accumulation at filopodia tips. Previous studies have mapped the RAPH1 interaction domain for adhesome components to its talin-binding and Ras-association domains. Surprisingly, we find that the RAPH1 MYO10-binding site is not within these domains. Instead, it comprises a conserved helix located just after the RAPH1 pleckstrin homology domain with previously unknown functions. Functionally, RAPH1 supports MYO10 filopodia formation and stability but is not required to activate integrins at filopodia tips. Taken together, our data indicate a feed-forward mechanism whereby MYO10 filopodia are positively regulated by MYO10-mediated transport of RAPH1 to the filopodium tip.
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Affiliation(s)
- Ana Popović
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland.,Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, 20520 Turku, Finland
| | - Mitro Miihkinen
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Sujan Ghimire
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland.,Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, 20520 Turku, Finland
| | - Rafael Saup
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Max L B Grönloh
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland
| | - Neil J Ball
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Benjamin T Goult
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Johanna Ivaska
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland.,Department of Life Technologies, University of Turku, 20520 Turku, Finland.,InFLAMES Research Flagship Center, University of Turku and Åbo Akademi University, 20520 Turku, Finland.,Western Finnish Cancer Center (FICAN West), University of Turku, 20520 Turku, Finland
| | - Guillaume Jacquemet
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, 20520 Turku, Finland.,Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, 20520 Turku, Finland.,InFLAMES Research Flagship Center, University of Turku and Åbo Akademi University, 20520 Turku, Finland.,Turku Bioimaging, University of Turku and Åbo Akademi University, 20520 Turku, Finland
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4
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Neogenin suppresses tumor progression and metastasis via inhibiting Merlin/YAP signaling. Cell Death Dis 2023; 9:47. [PMID: 36746934 PMCID: PMC9902585 DOI: 10.1038/s41420-023-01345-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 01/24/2023] [Accepted: 01/26/2023] [Indexed: 02/08/2023]
Abstract
From in situ growth to invasive dissemination is the most lethal attribute of various tumor types. This transition is majorly mediated by the dynamic interplay between two cancer hallmarks, EMT and cell cycle. In this study, we applied nonlinear association analysis in 33 cancer types and found that most signaling receptors simultaneously associating with EMT and cell cycle are potential tumor suppressors. Here we find that a top co-associated receptor, Neogenin (NEO1), inhibits colorectal cancer (CRC) and Glioma in situ growth and metastasis by forming a complex with Merlin (NF2), and subsequent simultaneous promoting the phosphorylation of YAP. Furthermore, Neogenin protein level is associated with good prognosis and correlates with Merlin status in CRC and Glioma. Collectively, our results define Neogenin as a tumor suppressor in CRC and Glioma that acts by restricting oncogenic signaling by the Merlin-YAP pathway, and suggest Neogenin as a candidate therapeutic agent for CRC and Glioma.
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5
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Myosin-X and talin modulate integrin activity at filopodia tips. Cell Rep 2021; 36:109716. [PMID: 34525374 PMCID: PMC8456781 DOI: 10.1016/j.celrep.2021.109716] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 07/06/2021] [Accepted: 08/24/2021] [Indexed: 11/20/2022] Open
Abstract
Filopodia assemble unique integrin-adhesion complexes to sense the extracellular matrix. However, the mechanisms of integrin regulation in filopodia are poorly defined. Here, we report that active integrins accumulate at the tip of myosin-X (MYO10)-positive filopodia, while inactive integrins are uniformly distributed. We identify talin and MYO10 as the principal integrin activators in filopodia. In addition, deletion of MYO10's FERM domain, or mutation of its β1-integrin-binding residues, reveals MYO10 as facilitating integrin activation, but not transport, in filopodia. However, MYO10's isolated FERM domain alone cannot activate integrins, potentially because of binding to both integrin tails. Finally, because a chimera construct generated by swapping MYO10-FERM by talin-FERM enables integrin activation in filopodia, our data indicate that an integrin-binding FERM domain coupled to a myosin motor is a core requirement for integrin activation in filopodia. Therefore, we propose a two-step integrin activation model in filopodia: receptor tethering by MYO10 followed by talin-mediated integrin activation.
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6
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Morcom L, Gobius I, Marsh APL, Suárez R, Lim JWC, Bridges C, Ye Y, Fenlon LR, Zagar Y, Douglass AM, Donahoo ALS, Fothergill T, Shaikh S, Kozulin P, Edwards TJ, Cooper HM, Sherr EH, Chédotal A, Leventer RJ, Lockhart PJ, Richards LJ. DCC regulates astroglial development essential for telencephalic morphogenesis and corpus callosum formation. eLife 2021; 10:e61769. [PMID: 33871356 PMCID: PMC8116049 DOI: 10.7554/elife.61769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 04/18/2021] [Indexed: 02/04/2023] Open
Abstract
The forebrain hemispheres are predominantly separated during embryogenesis by the interhemispheric fissure (IHF). Radial astroglia remodel the IHF to form a continuous substrate between the hemispheres for midline crossing of the corpus callosum (CC) and hippocampal commissure (HC). Deleted in colorectal carcinoma (DCC) and netrin 1 (NTN1) are molecules that have an evolutionarily conserved function in commissural axon guidance. The CC and HC are absent in Dcc and Ntn1 knockout mice, while other commissures are only partially affected, suggesting an additional aetiology in forebrain commissure formation. Here, we find that these molecules play a critical role in regulating astroglial development and IHF remodelling during CC and HC formation. Human subjects with DCC mutations display disrupted IHF remodelling associated with CC and HC malformations. Thus, axon guidance molecules such as DCC and NTN1 first regulate the formation of a midline substrate for dorsal commissures prior to their role in regulating axonal growth and guidance across it.
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Affiliation(s)
- Laura Morcom
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Ilan Gobius
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Ashley PL Marsh
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children’s Research Institute, Royal Children’s HospitalParkvilleAustralia
- Department of Paediatrics, University of MelbourneParkvilleAustralia
| | - Rodrigo Suárez
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Jonathan WC Lim
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Caitlin Bridges
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Yunan Ye
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Laura R Fenlon
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Yvrick Zagar
- Sorbonne Université, INSERM, CNRS, Institut de la VisionParisFrance
| | - Amelia M Douglass
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | | | - Thomas Fothergill
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Samreen Shaikh
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Peter Kozulin
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - Timothy J Edwards
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
- The University of Queensland, Faculty of MedicineBrisbaneAustralia
| | - Helen M Cooper
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
| | - IRC5 Consortium
- Members and Affiliates of the International Research Consortium for the Corpus Callosum and Cerebral Connectivity (IRC5)Los AngelesUnited States
| | - Elliott H Sherr
- Departments of Neurology and Pediatrics, Institute of Human Genetics and Weill Institute of Neurosciences, University of California, San FranciscoSan FranciscoUnited States
| | - Alain Chédotal
- Sorbonne Université, INSERM, CNRS, Institut de la VisionParisFrance
| | - Richard J Leventer
- Department of Paediatrics, University of MelbourneParkvilleAustralia
- Neuroscience Research Group, Murdoch Children’s Research InstituteParkvilleAustralia
- Department of Neurology, University of Melbourne, Royal Children’s HospitalParkvilleAustralia
| | - Paul J Lockhart
- Bruce Lefroy Centre for Genetic Health Research, Murdoch Children’s Research Institute, Royal Children’s HospitalParkvilleAustralia
- Department of Paediatrics, University of MelbourneParkvilleAustralia
| | - Linda J Richards
- The University of Queensland, Queensland Brain InstituteBrisbaneAustralia
- The University of Queensland, School of Biomedical SciencesBrisbaneAustralia
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7
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Hall ET, Dillard ME, Stewart DP, Zhang Y, Wagner B, Levine RM, Pruett-Miller SM, Sykes A, Temirov J, Cheney RE, Mori M, Robinson CG, Ogden SK. Cytoneme delivery of Sonic Hedgehog from ligand-producing cells requires Myosin 10 and a Dispatched-BOC/CDON co-receptor complex. eLife 2021; 10:61432. [PMID: 33570491 PMCID: PMC7968926 DOI: 10.7554/elife.61432] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 02/10/2021] [Indexed: 12/13/2022] Open
Abstract
Morphogens function in concentration-dependent manners to instruct cell fate during tissue patterning. The cytoneme morphogen transport model posits that specialized filopodia extend between morphogen-sending and responding cells to ensure that appropriate signaling thresholds are achieved. How morphogens are transported along and deployed from cytonemes, how quickly a cytoneme-delivered, receptor-dependent signal is initiated, and whether these processes are conserved across phyla are not known. Herein, we reveal that the actin motor Myosin 10 promotes vesicular transport of Sonic Hedgehog (SHH) morphogen in mouse cell cytonemes, and that SHH morphogen gradient organization is altered in neural tubes of Myo10-/- mice. We demonstrate that cytoneme-mediated deposition of SHH onto receiving cells induces a rapid, receptor-dependent signal response that occurs within seconds of ligand delivery. This activity is dependent upon a novel Dispatched (DISP)-BOC/CDON co-receptor complex that functions in ligand-producing cells to promote cytoneme occurrence and facilitate ligand delivery for signal activation.
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Affiliation(s)
- Eric T Hall
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Miriam E Dillard
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Daniel P Stewart
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Yan Zhang
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Ben Wagner
- Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, United States
| | - Rachel M Levine
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, United States
| | - Shondra M Pruett-Miller
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, United States
| | - April Sykes
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, United States
| | - Jamshid Temirov
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Richard E Cheney
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, United States
| | - Motomi Mori
- Department of Biostatistics, St. Jude Children's Research Hospital, Memphis, United States
| | - Camenzind G Robinson
- Cell and Tissue Imaging Center, St. Jude Children's Research Hospital, Memphis, United States
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
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9
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The netrin receptor UNC-40/DCC assembles a postsynaptic scaffold and sets the synaptic content of GABA A receptors. Nat Commun 2020; 11:2674. [PMID: 32471987 PMCID: PMC7260190 DOI: 10.1038/s41467-020-16473-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 04/28/2020] [Indexed: 01/11/2023] Open
Abstract
Increasing evidence indicates that guidance molecules used during development for cellular and axonal navigation also play roles in synapse maturation and homeostasis. In C. elegans the netrin receptor UNC-40/DCC controls the growth of dendritic-like muscle cell extensions towards motoneurons and is required to recruit type A GABA receptors (GABAARs) at inhibitory neuromuscular junctions. Here we show that activation of UNC-40 assembles an intracellular synaptic scaffold by physically interacting with FRM-3, a FERM protein orthologous to FARP1/2. FRM-3 then recruits LIN-2, the ortholog of CASK, that binds the synaptic adhesion molecule NLG-1/Neuroligin and physically connects GABAARs to prepositioned NLG-1 clusters. These processes are orchestrated by the synaptic organizer CePunctin/MADD-4, which controls the localization of GABAARs by positioning NLG-1/neuroligin at synapses and regulates the synaptic content of GABAARs through the UNC-40-dependent intracellular scaffold. Since DCC is detected at GABA synapses in mammals, DCC might also tune inhibitory neurotransmission in the mammalian brain. The netrin receptor UNC-40/DCC is required to recruit GABAAR at neuromuscular junctions in C. elegans. Here, the authors show that UNC-40/DCC assembles an intracellular synaptic scaffold, regulating the content of GABAAR and inhibitory neurotransmission.
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10
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11
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Motor-cargo adaptors at the organelle-cytoskeleton interface. Curr Opin Cell Biol 2019; 59:16-23. [PMID: 30952037 DOI: 10.1016/j.ceb.2019.02.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 02/15/2019] [Accepted: 02/26/2019] [Indexed: 01/03/2023]
Abstract
Cytoskeletal motors of the dynein, kinesin and myosin superfamilies maintain and adapt subcellular organelle organization to meet functional demands and support the vesicular transport of material between organelles. These motors require the capacity to specifically recognize the vesicle/organelle to be transported and are capable of selective recognition of multiple cargo. Recent studies have begun to uncover the molecular basis for motor recruitment and have highlighted the role of organelle-associated 'cargo-adaptor' proteins in cellular transport. These adaptors possess sequences and/or structural features that enable both motor recruitment and activation from regulated, inactive, states to enable motility on the cytoskeleton. Motor-cargo adaptor interactions define a key organelle-cytoskeleton interface, acting as crucial regulatory hubs to enable the cell to finely control membrane trafficking and organelle dynamics. Understanding the molecular basis of these interactions may offer new opportunities to control and manipulate cytoskeletal and organelle dynamics for the development of new research tools and potentially therapeutics.
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Mehregan H, Mohseni M, Jalalvand K, Arzhangi S, Nikzat N, Banihashemi S, Kahrizi K, Najmabadi H. Novel mutations in MYTH4-FERM domains of myosin 15 are associated with autosomal recessive nonsyndromic hearing loss. Int J Pediatr Otorhinolaryngol 2019; 117:115-126. [PMID: 30579064 DOI: 10.1016/j.ijporl.2018.11.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 11/20/2018] [Accepted: 11/20/2018] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Hereditary hearing loss is the most common neurosensory disorder in humans caused by myriad mutations in numerous genes. Autosomal recessive nonsyndromic hearing loss (ARNSHL) accounts for 80% of hearing impairments of genetic origin and is quite prevalent in societies with a high rate of consanguinity. In the current study, we investigated the causes of sensorineural hearing loss in 24 unrelated Iranian families who were mainly consanguineous and had at least two affected children. METHODS All probands were initially screened for GJB2 mutations, as the most common causes of ARNSHL in Iran. Verified GJB2-negative samples were subsequently subjected to whole exome sequencing (WES) to identify the underlying causes of hearing impairment, and the variants identified in each family were further confirmed by Sanger sequencing. RESULTS WES revealed three previously unreported mutations in MYO15A, the gene encoding the unconventional myosin 15 (Myo15). All variants identified, c.C6436T (p.R2146W), c.C9584G (p.P3195R) and c.G10266C (p.Q3422H), reside in the MYTH4 (myosin tail homology) and FERM (4.1 ezrin, radixin, moesin) domains of the protein. CONCLUSION Globally, mutations in MYO15A are considered to be among the most prevalent genetic causes of ARNSHL, and they rank as the third leading cause of hearing loss in the Iranian population, below GJB2 and SLC26A4. Yet again, these results endorse the importance of MYO15 screening in hearing impaired populations, particularly in Iran.
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Affiliation(s)
- Hoda Mehregan
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Marzieh Mohseni
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Khadijeh Jalalvand
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Sanaz Arzhangi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Nooshin Nikzat
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Sussan Banihashemi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Kimia Kahrizi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hossein Najmabadi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
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13
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Bachg AC, Horsthemke M, Skryabin BV, Klasen T, Nagelmann N, Faber C, Woodham E, Machesky LM, Bachg S, Stange R, Jeong HW, Adams RH, Bähler M, Hanley PJ. Phenotypic analysis of Myo10 knockout (Myo10 tm2/tm2) mice lacking full-length (motorized) but not brain-specific headless myosin X. Sci Rep 2019; 9:597. [PMID: 30679680 PMCID: PMC6345916 DOI: 10.1038/s41598-018-37160-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 12/04/2018] [Indexed: 01/04/2023] Open
Abstract
We investigated the physiological functions of Myo10 (myosin X) using Myo10 reporter knockout (Myo10tm2) mice. Full-length (motorized) Myo10 protein was deleted, but the brain-specific headless (Hdl) isoform (Hdl-Myo10) was still expressed in homozygous mutants. In vitro, we confirmed that Hdl-Myo10 does not induce filopodia, but it strongly localized to the plasma membrane independent of the MyTH4-FERM domain. Filopodia-inducing Myo10 is implicated in axon guidance and mice lacking the Myo10 cargo protein DCC (deleted in colorectal cancer) have severe commissural defects, whereas MRI (magnetic resonance imaging) of isolated brains revealed intact commissures in Myo10tm2/tm2 mice. However, reminiscent of Waardenburg syndrome, a neural crest disorder, Myo10tm2/tm2 mice exhibited pigmentation defects (white belly spots) and simple syndactyly with high penetrance (>95%), and 24% of mutant embryos developed exencephalus, a neural tube closure defect. Furthermore, Myo10tm2/tm2 mice consistently displayed bilateral persistence of the hyaloid vasculature, revealed by MRI and retinal whole-mount preparations. In principle, impaired tissue clearance could contribute to persistence of hyaloid vasculature and syndactyly. However, Myo10-deficient macrophages exhibited no defects in the phagocytosis of apoptotic or IgG-opsonized cells. RNA sequence analysis showed that Myo10 was the most strongly expressed unconventional myosin in retinal vascular endothelial cells and expression levels increased 4-fold between P6 and P15, when vertical sprouting angiogenesis gives rise to deeper layers. Nevertheless, imaging of isolated adult mutant retinas did not reveal vascularization defects. In summary, Myo10 is important for both prenatal (neural tube closure and digit formation) and postnatal development (hyaloid regression, but not retinal vascularization).
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Affiliation(s)
- Anne C Bachg
- Institut für Molekulare Zellbiologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Markus Horsthemke
- Institut für Molekulare Zellbiologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Boris V Skryabin
- Department of Medicine, Transgenic Animal and Genetic Engineering Models (TRAM), Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Tim Klasen
- Department of Clinical Radiology, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Nina Nagelmann
- Department of Clinical Radiology, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Cornelius Faber
- Department of Clinical Radiology, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Emma Woodham
- Cancer Research UK Beatson Institute, Glasgow University College of Medical, Veterinary and Life Sciences Garscube Estate, Glasgow, G61 1BD, United Kingdom
| | - Laura M Machesky
- Cancer Research UK Beatson Institute, Glasgow University College of Medical, Veterinary and Life Sciences Garscube Estate, Glasgow, G61 1BD, United Kingdom
| | - Sandra Bachg
- Department of Regenerative Musculoskeletal Medicine, Institute of Musculoskeletal Medicine (IMM), University Hospital Münster, 48149, Münster, Germany
| | - Richard Stange
- Department of Regenerative Musculoskeletal Medicine, Institute of Musculoskeletal Medicine (IMM), University Hospital Münster, 48149, Münster, Germany
| | - Hyun-Woo Jeong
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Münster, Faculty of Medicine, 48149, Münster, Germany
| | - Ralf H Adams
- Max Planck Institute for Molecular Biomedicine, Department of Tissue Morphogenesis, and University of Münster, Faculty of Medicine, 48149, Münster, Germany
| | - Martin Bähler
- Institut für Molekulare Zellbiologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany
| | - Peter J Hanley
- Institut für Molekulare Zellbiologie, Westfälische Wilhelms-Universität Münster, 48149, Münster, Germany.
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14
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Boyer NP, Gupton SL. Revisiting Netrin-1: One Who Guides (Axons). Front Cell Neurosci 2018; 12:221. [PMID: 30108487 PMCID: PMC6080411 DOI: 10.3389/fncel.2018.00221] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/09/2018] [Indexed: 12/28/2022] Open
Abstract
Proper patterning of the nervous system requires that developing axons find appropriate postsynaptic partners; this entails microns to meters of extension through an extracellular milieu exhibiting a wide range of mechanical and chemical properties. Thus, the elaborate networks of fiber tracts and non-fasciculated axons evident in mature organisms are formed via complex pathfinding. The macroscopic structures of axon projections are highly stereotyped across members of the same species, indicating precise mechanisms guide their formation. The developing axon exhibits directionally biased growth toward or away from external guidance cues. One of the most studied guidance cues is netrin-1, however, its presentation in vivo remains debated. Guidance cues can be secreted to form soluble or chemotactic gradients or presented bound to cells or the extracellular matrix to form haptotactic gradients. The growth cone, a highly specialized dynamic structure at the end of the extending axon, detects these guidance cues via transmembrane receptors, such as the netrin-1 receptors deleted in colorectal cancer (DCC) and UNC5. These receptors orchestrate remodeling of the cytoskeleton and cell membrane through both chemical and mechanotransductive pathways, which result in traction forces generated by the cytoskeleton against the extracellular environment and translocation of the growth cone. Through intracellular signaling responses, netrin-1 can trigger either attraction or repulsion of the axon. Here we review the mechanisms by which the classical guidance cue netrin-1 regulates intracellular effectors to respond to the extracellular environment in the context of axon guidance during development of the central nervous system and discuss recent findings that demonstrate the critical importance of mechanical forces in this process.
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Affiliation(s)
- Nicholas P. Boyer
- Neurobiology Curriculum, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Stephanie L. Gupton
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Neuroscience Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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15
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16
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The binding of DCC-P3 motif and FAK-FAT domain mediates the initial step of netrin-1/DCC signaling for axon attraction. Cell Discov 2018; 4:8. [PMID: 29479476 PMCID: PMC5818605 DOI: 10.1038/s41421-017-0008-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 12/17/2017] [Accepted: 12/22/2017] [Indexed: 01/05/2023] Open
Abstract
Netrin-1 plays a key role in axon guidance through binding to its receptor, Deleted in Colorectal Cancer (DCC). The initial step of signaling inside the cell after netrin-1/DCC ligation is the binding of DCC cytoplasmic P3 motif to focal adhesion targeting (FAT) domain of focal adhesion kinase (FAK). Here we report the crystal structure of P3/FAT complex. The helical P3 peptide interacts with a helix-swapped FAT dimer in a 2:2 ratio. Dimeric FAT binding is P3-specific and stabilized by a calcium ion. Biochemical studies showed that DCC-P3 motif and calcium ion could facilitate FAT dimerization in solution. Axon guidance assays confirm that the DCC/FAK complex is essential for netrin-1-induced chemoattraction. We propose that netrin-1/DCC engagement creates a small cluster of P3/FAT for FAK recruitment close to the cell membrane, which exerts a concerted effect with PIP2 for FAK signaling. We also compare P3/FAT binding with paxillin/FAT binding and discuss their distinct recognition specificity on a common FAT domain for axon attraction versus integrin signaling, respectively.
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17
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Sandquist JC, Larson ME, Woolner S, Ding Z, Bement WM. An interaction between myosin-10 and the cell cycle regulator Wee1 links spindle dynamics to mitotic progression in epithelia. J Cell Biol 2018; 217:849-859. [PMID: 29321170 PMCID: PMC5839792 DOI: 10.1083/jcb.201708072] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 11/20/2017] [Accepted: 12/06/2017] [Indexed: 01/02/2023] Open
Abstract
Proper spindle orientation must be achieved before anaphase onset, but whether and how cells link spindle position to anaphase onset is unknown. Sandquist, Larson, et al. identify a novel interaction between the motor protein myosin-10 and the cell cycle regulator wee1 that is proposed to help coordinate preanaphase spindle dynamics and positioning with mitotic exit. Anaphase in epithelia typically does not ensue until after spindles have achieved a characteristic position and orientation, but how or even if cells link spindle position to anaphase onset is unknown. Here, we show that myosin-10 (Myo10), a motor protein involved in epithelial spindle dynamics, binds to Wee1, a conserved regulator of cyclin-dependent kinase 1 (Cdk1). Wee1 inhibition accelerates progression through metaphase and disrupts normal spindle dynamics, whereas perturbing Myo10 function delays anaphase onset in a Wee1-dependent manner. Moreover, Myo10 perturbation increases Wee1-mediated inhibitory phosphorylation on Cdk1, which, unexpectedly, concentrates at cell–cell junctions. Based on these and other results, we propose a model in which the Myo10–Wee1 interaction coordinates attainment of spindle position and orientation with anaphase onset.
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Affiliation(s)
- Joshua C Sandquist
- Biology Department, Grinnell College, Grinnell, IA .,Department of Zoology, University of Wisconsin-Madison, Madison, WI
| | - Matthew E Larson
- Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI.,Medical Scientist Training Program, University of Wisconsin-Madison, Madison, WI
| | - Sarah Woolner
- Department of Zoology, University of Wisconsin-Madison, Madison, WI.,Wellcome Trust Centre for Cell-Matrix Research, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, England, UK
| | - Zhiwei Ding
- Biology Department, Grinnell College, Grinnell, IA
| | - William M Bement
- Department of Zoology, University of Wisconsin-Madison, Madison, WI .,Cellular and Molecular Biology Graduate Program, University of Wisconsin-Madison, Madison, WI.,Medical Scientist Training Program, University of Wisconsin-Madison, Madison, WI.,Laboratory of Cell and Molecular Biology, University of Wisconsin-Madison, Madison, WI
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18
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Structural basis of kindlin-mediated integrin recognition and activation. Proc Natl Acad Sci U S A 2017; 114:9349-9354. [PMID: 28739949 DOI: 10.1073/pnas.1703064114] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Kindlins and talins are integrin-binding proteins that are critically involved in integrin activation, an essential process for many fundamental cellular activities including cell-matrix adhesion, migration, and proliferation. As FERM-domain-containing proteins, talins and kindlins, respectively, bind different regions of β-integrin cytoplasmic tails. However, compared with the extensively studied talin, little is known about how kindlins specifically interact with integrins and synergistically enhance their activation by talins. Here, we determined crystal structures of kindlin2 in the apo-form and the β1- and β3-integrin bound forms. The apo-structure shows an overall architecture distinct from talins. The complex structures reveal a unique integrin recognition mode of kindlins, which combines two binding motifs to provide specificity that is essential for integrin activation and signaling. Strikingly, our structures uncover an unexpected dimer formation of kindlins. Interrupting dimer formation impairs kindlin-mediated integrin activation. Collectively, the structural, biochemical, and cellular results provide mechanistic explanations that account for the effects of kindlins on integrin activation as well as for how kindlin mutations found in patients with Kindler syndrome and leukocyte-adhesion deficiency may impact integrin-mediated processes.
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19
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Myosin 7 and its adaptors link cadherins to actin. Nat Commun 2017; 8:15864. [PMID: 28660889 PMCID: PMC5493754 DOI: 10.1038/ncomms15864] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 05/03/2017] [Indexed: 12/17/2022] Open
Abstract
Cadherin linkages between adjacent stereocilia and microvilli are essential for mechanotransduction and maintaining their organization. They are anchored to actin through interaction of their cytoplasmic domains with related tripartite complexes consisting of a class VII myosin and adaptor proteins: Myo7a/SANS/Harmonin in stereocilia and Myo7b/ANKS4B/Harmonin in microvilli. Here, we determine high-resolution structures of Myo7a and Myo7b C-terminal MyTH4-FERM domain (MF2) and unveil how they recognize harmonin using a novel binding mode. Systematic definition of interactions between domains of the tripartite complex elucidates how the complex assembles and prevents possible self-association of harmonin-a. Several Myo7a deafness mutants that map to the surface of MF2 disrupt harmonin binding, revealing the molecular basis for how they impact the formation of the tripartite complex and disrupt mechanotransduction. Our results also suggest how switching between different harmonin isoforms can regulate the formation of networks with Myo7a motors and coordinate force sensing in stereocilia. Cadherin is essential for mechanotransduction and myosin-adaptor-harmonin complexes anchor it to actin. Here the authors present the structures of myosin 7 MF2 domains bound to the harmonin PDZ3c domain and give insights into myosin-adaptor-harmonin complex assembly.
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20
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Structure of Myo7b/USH1C complex suggests a general PDZ domain binding mode by MyTH4-FERM myosins. Proc Natl Acad Sci U S A 2017; 114:E3776-E3785. [PMID: 28439001 DOI: 10.1073/pnas.1702251114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unconventional myosin 7a (Myo7a), myosin 7b (Myo7b), and myosin 15a (Myo15a) all contain MyTH4-FERM domains (myosin tail homology 4-band 4.1, ezrin, radixin, moesin; MF) in their cargo binding tails and are essential for the growth and function of microvilli and stereocilia. Numerous mutations have been identified in the MyTH4-FERM tandems of these myosins in patients suffering visual and hearing impairment. Although a number of MF domain binding partners have been identified, the molecular basis of interactions with the C-terminal MF domain (CMF) of these myosins remains poorly understood. Here we report the high-resolution crystal structure of Myo7b CMF in complex with the extended PDZ3 domain of USH1C (a.k.a., Harmonin), revealing a previously uncharacterized interaction mode both for MyTH4-FERM tandems and for PDZ domains. We predicted, based on the structure of the Myo7b CMF/USH1C PDZ3 complex, and verified that Myo7a CMF also binds to USH1C PDZ3 using a similar mode. The structure of the Myo7b CMF/USH1C PDZ complex provides mechanistic explanations for >20 deafness-causing mutations in Myo7a CMF. Taken together, these findings suggest that binding to PDZ domains, such as those from USH1C, PDZD7, and Whirlin, is a common property of CMFs of Myo7a, Myo7b, and Myo15a.
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21
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Masters TA, Kendrick-Jones J, Buss F. Myosins: Domain Organisation, Motor Properties, Physiological Roles and Cellular Functions. Handb Exp Pharmacol 2017; 235:77-122. [PMID: 27757761 DOI: 10.1007/164_2016_29] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Myosins are cytoskeletal motor proteins that use energy derived from ATP hydrolysis to generate force and movement along actin filaments. Humans express 38 myosin genes belonging to 12 classes that participate in a diverse range of crucial activities, including muscle contraction, intracellular trafficking, cell division, motility, actin cytoskeletal organisation and cell signalling. Myosin malfunction has been implicated a variety of disorders including deafness, hypertrophic cardiomyopathy, Usher syndrome, Griscelli syndrome and cancer. In this chapter, we will first discuss the key structural and kinetic features that are conserved across the myosin family. Thereafter, we summarise for each member in turn its unique functional and structural adaptations, cellular roles and associated pathologies. Finally, we address the broad therapeutic potential for pharmacological interventions that target myosin family members.
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Affiliation(s)
- Thomas A Masters
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
| | | | - Folma Buss
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
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22
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Ferrao R, Lupardus PJ. The Janus Kinase (JAK) FERM and SH2 Domains: Bringing Specificity to JAK-Receptor Interactions. Front Endocrinol (Lausanne) 2017; 8:71. [PMID: 28458652 PMCID: PMC5394478 DOI: 10.3389/fendo.2017.00071] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 03/27/2017] [Indexed: 12/24/2022] Open
Abstract
The Janus kinases (JAKs) are non-receptor tyrosine kinases essential for signaling in response to cytokines and interferons and thereby control many essential functions in growth, development, and immune regulation. JAKs are unique among tyrosine kinases for their constitutive yet non-covalent association with class I and II cytokine receptors, which upon cytokine binding bring together two JAKs to create an active signaling complex. JAK association with cytokine receptors is facilitated by N-terminal FERM and SH2 domains, both of which are classical mediators of peptide interactions. Together, the JAK FERM and SH2 domains mediate a bipartite interaction with two distinct receptor peptide motifs, the proline-rich "Box1" and hydrophobic "Box2," which are present in the intracellular domain of cytokine receptors. While the general sidechain chemistry of Box1 and Box2 peptides is conserved between receptors, they share very weak primary sequence homology, making it impossible to posit why certain JAKs preferentially interact with and signal through specific subsets of cytokine receptors. Here, we review the structure and function of the JAK FERM and SH2 domains in light of several recent studies that reveal their atomic structure and elucidate interaction mechanisms with both the Box1 and Box2 receptor motifs. These crystal structures demonstrate how evolution has repurposed the JAK FERM and SH2 domains into a receptor-binding module that facilitates interactions with multiple receptors possessing diverse primary sequences.
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Affiliation(s)
- Ryan Ferrao
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA
| | - Patrick J. Lupardus
- Department of Structural Biology, Genentech Inc., South San Francisco, CA, USA
- *Correspondence: Patrick J. Lupardus,
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23
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MyTH4-FERM myosins have an ancient and conserved role in filopod formation. Proc Natl Acad Sci U S A 2016; 113:E8059-E8068. [PMID: 27911821 DOI: 10.1073/pnas.1615392113] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The formation of filopodia in Metazoa and Amoebozoa requires the activity of myosin 10 (Myo10) in mammalian cells and of Dictyostelium unconventional myosin 7 (DdMyo7) in the social amoeba Dictyostelium However, the exact roles of these MyTH4-FERM myosins (myosin tail homology 4-band 4.1, ezrin, radixin, moesin; MF) in the initiation and elongation of filopodia are not well defined and may reflect conserved functions among phylogenetically diverse MF myosins. Phylogenetic analysis of MF myosin domains suggests that a single ancestral MF myosin existed with a structure similar to DdMyo7, which has two MF domains, and that subsequent duplications in the metazoan lineage produced its functional homolog Myo10. The essential functional features of the DdMyo7 myosin were identified using quantitative live-cell imaging to characterize the ability of various mutants to rescue filopod formation in myo7-null cells. The two MF domains were found to function redundantly in filopod formation with the C-terminal FERM domain regulating both the number of filopodia and their elongation velocity. DdMyo7 mutants consisting solely of the motor plus a single MyTH4 domain were found to be capable of rescuing the formation of filopodia, establishing the minimal elements necessary for the function of this myosin. Interestingly, a chimeric myosin with the Myo10 MF domain fused to the DdMyo7 motor also was capable of rescuing filopod formation in the myo7-null mutant, supporting fundamental functional conservation between these two distant myosins. Together, these findings reveal that MF myosins have an ancient and conserved role in filopod formation.
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24
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Weck ML, Grega-Larson NE, Tyska MJ. MyTH4-FERM myosins in the assembly and maintenance of actin-based protrusions. Curr Opin Cell Biol 2016; 44:68-78. [PMID: 27836411 DOI: 10.1016/j.ceb.2016.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/12/2016] [Indexed: 12/13/2022]
Abstract
Unconventional myosins are actin-based molecular motors that serve a multitude of roles within the cell. One group of myosin motors, the MyTH4-FERM myosins, play an integral part in building and maintaining finger-like protrusions, which allow cells to interact with their external environment. Suggested to act primarily as transporters, these motor proteins enrich adhesion molecules, actin-regulatory proteins and other factors at the tips of filopodia, microvilli, and stereocilia. Below we review data from biophysical, biochemical, and cell biological studies, which implicate these myosins as central players in the assembly, maintenance and function of actin-based protrusions.
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Affiliation(s)
- Meredith L Weck
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, 3154 MRB III, PMB 407935, 465 21st Avenue South, Nashville, TN 37240-7935, United States
| | - Nathan E Grega-Larson
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, 3154 MRB III, PMB 407935, 465 21st Avenue South, Nashville, TN 37240-7935, United States
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, 3154 MRB III, PMB 407935, 465 21st Avenue South, Nashville, TN 37240-7935, United States.
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25
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Baboolal TG, Mashanov GI, Nenasheva TA, Peckham M, Molloy JE. A Combination of Diffusion and Active Translocation Localizes Myosin 10 to the Filopodial Tip. J Biol Chem 2016; 291:22373-22385. [PMID: 27566544 PMCID: PMC5077179 DOI: 10.1074/jbc.m116.730689] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 08/24/2016] [Indexed: 11/06/2022] Open
Abstract
Myosin 10 is an actin-based molecular motor that localizes to the tips of filopodia in mammalian cells. To understand how it is targeted to this distinct region of the cell, we have used total internal reflection fluorescence microscopy to study the movement of individual full-length and truncated GFP-tagged molecules. Truncation mutants lacking the motor region failed to localize to filopodial tips but still bound transiently at the plasma membrane. Deletion of the single α-helical and anti-parallel coiled-coil forming regions, which lie between the motor and pleckstrin homology domains, reduced the instantaneous velocity of intrafilopodial movement but did not affect the number of substrate adherent filopodia. Deletion of the anti-parallel coiled-coil forming region, but not the EKR-rich region of the single α-helical domain, restored intrafilopodial trafficking, suggesting this region is important in determining myosin 10 motility. We propose a model by which myosin 10 rapidly targets to the filopodial tip via a sequential reduction in dimensionality. Molecules first undergo rapid diffusion within the three-dimensional volume of the cell body. They then exhibit periods of slower two-dimensional diffusion in the plane of the plasma membrane. Finally, they move in a unidimensional, highly directed manner along the polarized actin filament bundle within the filopodium becoming confined to a single point at the tip. Here we have observed directly each phase of the trafficking process using single molecule fluorescence imaging of live cells and have quantified our observations using single particle tracking, autocorrelation analysis, and kymographs.
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Affiliation(s)
- Thomas G Baboolal
- From the Astbury Centre for Structural Molecular Biology and Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and
| | - Gregory I Mashanov
- The Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, United Kingdom
| | - Tatiana A Nenasheva
- The Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, United Kingdom
| | - Michelle Peckham
- From the Astbury Centre for Structural Molecular Biology and Institute of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT and
| | - Justin E Molloy
- The Francis Crick Institute, Mill Hill Laboratory, London NW7 1AA, United Kingdom
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26
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Sandquist JC, Larson ME, Hine KJ. Myosin-10 independently influences mitotic spindle structure and mitotic progression. Cytoskeleton (Hoboken) 2016; 73:351-64. [PMID: 27220038 DOI: 10.1002/cm.21311] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 05/17/2016] [Accepted: 05/20/2016] [Indexed: 12/30/2022]
Abstract
The iconic bipolar structure of the mitotic spindle is of extreme importance to proper spindle function. At best, spindle abnormalities result in a delayed mitosis, while worse outcomes include cell death or disease. Recent work has uncovered an important role for the actin-based motor protein myosin-10 in the regulation of spindle structure and function. Here we examine the contribution of the myosin tail homology 4 (MyTH4) domain of the myosin-10 tail to the protein's spindle functions. The MyTH4 domain is known to mediate binding to microtubules and we verify the suspicion that this domain contributes to myosin-10's close association with the spindle. More surprisingly, our data demonstrate that some but not all of myosin-10's spindle functions require microtubule binding. In particular, myosin-10's contribution to spindle pole integrity requires microtubule binding, whereas its contribution to normal mitotic progression does not. This is demonstrated by the observation that dominant negative expression of the wild-type MyTH4 domain produces multipolar spindles and an increased mitotic index, whereas overexpression of a version of the MyTH4 domain harboring point mutations that abrogate microtubule binding results in only the mitotic index phenotype. Our data suggest that myosin-10 helps to control the metaphase to anaphase transition in cells independent of microtubule binding. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Joshua C Sandquist
- Biology Department, Grinnell College, Grinnell, Iowa.,Department of Zoology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Matthew E Larson
- Program in Cellular and Molecular Biology and the Medical Scientist Training Program, University of Wisconsin-Madison, Madison, Wisconsin
| | - Ken J Hine
- Biology Department, Grinnell College, Grinnell, Iowa
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27
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Mechanistic Basis of Organization of the Harmonin/USH1C-Mediated Brush Border Microvilli Tip-Link Complex. Dev Cell 2016; 36:179-89. [PMID: 26812017 DOI: 10.1016/j.devcel.2015.12.020] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/08/2015] [Accepted: 12/21/2015] [Indexed: 11/23/2022]
Abstract
Brush border microvilli are actin-based protrusions lining the apical surface of epithelial cells in intestines and proximal tubules of kidneys. While brush border microvilli resemble the relatively well-characterized stereocilia of hair cells, the mechanistic basis of tip-link complex organization in microvilli is poorly understood. Here, we have biochemically and structurally characterized the following pairs of interactions: protocadherin 24 and Harmonin (also known as USH1C or AIE-75), Harmonin and myosin VIIb (MYO7B), Harmonin and ANKS4B, and ANKS4B and MYO7B. We show that Harmonin, ANKS4B, and MYO7B form a stable ternary complex for anchoring microvilli tip-link cadherins. Despite having only Harmonin in common, the microvilli and the stereocilia tip-link complexes are formed via strikingly similar interaction modes. These results not only provide insight into the mechanistic bases of brush border microvilli formation and maintenance but may also be valuable for understanding some gut and/or kidney diseases caused by perturbations of brush border microvilli structures.
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28
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Myosin MyTH4-FERM structures highlight important principles of convergent evolution. Proc Natl Acad Sci U S A 2016; 113:E2906-15. [PMID: 27166421 DOI: 10.1073/pnas.1600736113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Myosins containing MyTH4-FERM (myosin tail homology 4-band 4.1, ezrin, radixin, moesin, or MF) domains in their tails are found in a wide range of phylogenetically divergent organisms, such as humans and the social amoeba Dictyostelium (Dd). Interestingly, evolutionarily distant MF myosins have similar roles in the extension of actin-filled membrane protrusions such as filopodia and bind to microtubules (MT), suggesting that the core functions of these MF myosins have been highly conserved over evolution. The structures of two DdMyo7 signature MF domains have been determined and comparison with mammalian MF structures reveals that characteristic features of MF domains are conserved. However, across millions of years of evolution conserved class-specific insertions are seen to alter the surfaces and the orientation of subdomains with respect to each other, likely resulting in new sites for binding partners. The MyTH4 domains of Myo10 and DdMyo7 bind to MT with micromolar affinity but, surprisingly, their MT binding sites are on opposite surfaces of the MyTH4 domain. The structural analysis in combination with comparison of diverse MF myosin sequences provides evidence that myosin tail domain features can be maintained without strict conservation of motifs. The results illustrate how tuning of existing features can give rise to new structures while preserving the general properties necessary for myosin tails. Thus, tinkering with the MF domain enables it to serve as a multifunctional platform for cooperative recruitment of various partners, allowing common properties such as autoinhibition of the motor and microtubule binding to arise through convergent evolution.
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29
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Li J, Lu Q, Zhang M. Structural Basis of Cargo Recognition by Unconventional Myosins in Cellular Trafficking. Traffic 2016; 17:822-38. [PMID: 26842936 DOI: 10.1111/tra.12383] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 01/17/2023]
Abstract
Unconventional myosins are a superfamily of actin-based molecular motors playing diverse roles including cellular trafficking, mechanical supports, force sensing and transmission, etc. The variable neck and tail domains of unconventional myosins function to bind to specific cargoes including proteins and lipid vesicles and thus are largely responsible for the diverse cellular functions of myosins in vivo. In addition, the tail regions, together with their cognate cargoes, can regulate activities of the motor heads. This review outlines the advances made in recent years on cargo recognition and cargo binding-induced regulation of the activity of several unconventional myosins including myosin-I, V, VI and X in cellular trafficking. We approach this topic by describing a series of high-resolution structures of the neck and tail domains of these unconventional myosins either alone or in complex with their specific cargoes, and by discussing potential implications of these structural studies on cellular trafficking of these myosin motors.
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Affiliation(s)
- Jianchao Li
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Qing Lu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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30
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Antoine-Bertrand J, Duquette PM, Alchini R, Kennedy TE, Fournier AE, Lamarche-Vane N. p120RasGAP Protein Mediates Netrin-1 Protein-induced Cortical Axon Outgrowth and Guidance. J Biol Chem 2015; 291:4589-602. [PMID: 26710849 DOI: 10.1074/jbc.m115.674846] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 12/23/2022] Open
Abstract
The receptor deleted in colorectal cancer (DCC) mediates the attraction of growing axons to netrin-1 during brain development. In response to netrin-1 stimulation, DCC becomes a signaling platform to recruit proteins that promote axon outgrowth and guidance. The Ras GTPase-activating protein (GAP) p120RasGAP inhibits Ras activity and mediates neurite retraction and growth cone collapse in response to repulsive guidance cues. Here we show an interaction between p120RasGAP and DCC that positively regulates netrin-1-mediated axon outgrowth and guidance in embryonic cortical neurons. In response to netrin-1, p120RasGAP is recruited to DCC in growth cones and forms a multiprotein complex with focal adhesion kinase and ERK. We found that Ras/ERK activities are elevated aberrantly in p120RasGAP-deficient neurons. Moreover, the expression of p120RasGAP Src homology 2 (SH2)-SH3-SH2 domains, which interact with the C-terminal tail of DCC, is sufficient to restore netrin-1-dependent axon outgrowth in p120RasGAP-deficient neurons. We provide a novel mechanism that exploits the scaffolding properties of the N terminus of p120RasGAP to tightly regulate netrin-1/DCC-dependent axon outgrowth and guidance.
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Affiliation(s)
- Judith Antoine-Bertrand
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
| | - Philippe M Duquette
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
| | - Ricardo Alchini
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Timothy E Kennedy
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Alyson E Fournier
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Nathalie Lamarche-Vane
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
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Neuhaus-Follini A, Bashaw GJ. The Intracellular Domain of the Frazzled/DCC Receptor Is a Transcription Factor Required for Commissural Axon Guidance. Neuron 2015; 87:751-63. [PMID: 26291159 DOI: 10.1016/j.neuron.2015.08.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 07/24/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022]
Abstract
In commissural neurons of Drosophila, the conserved Frazzled (Fra)/Deleted in Colorectal Cancer (DCC) receptor promotes midline axon crossing by signaling locally in response to Netrin and by inducing transcription of commissureless (comm), an antagonist of Slit-Roundabout midline repulsion, through an unknown mechanism. Here, we show that Fra is cleaved to release its intracellular domain (ICD), which shuttles between the cytoplasm and the nucleus, where it functions as a transcriptional activator. Rescue and gain-of-function experiments demonstrate that the Fra ICD is sufficient to regulate comm expression and that both γ-secretase proteolysis of Fra and Fra's function as a transcriptional activator are required for its ability to regulate comm in vivo. Our data uncover an unexpected role for the Fra ICD as a transcription factor whose activity regulates the responsiveness of commissural axons at the midline and raise the possibility that nuclear signaling may be a common output of axon guidance receptors.
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Affiliation(s)
- Alexandra Neuhaus-Follini
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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32
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Tian J, Han L, Feng Z, Wang G, Liu W, Ma Y, Yu Y, Kong Z. Orchestration of microtubules and the actin cytoskeleton in trichome cell shape determination by a plant-unique kinesin. eLife 2015; 4. [PMID: 26287478 PMCID: PMC4574192 DOI: 10.7554/elife.09351] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/18/2015] [Indexed: 11/13/2022] Open
Abstract
Microtubules (MTs) and actin filaments (F-actin) function cooperatively to regulate plant cell morphogenesis. However, the mechanisms underlying the crosstalk between these two cytoskeletal systems, particularly in cell shape control, remain largely unknown. In this study, we show that introduction of the MyTH4-FERM tandem into KCBP (kinesin-like calmodulin-binding protein) during evolution conferred novel functions. The MyTH4 domain and the FERM domain in the N-terminal tail of KCBP physically bind to MTs and F-actin, respectively. During trichome morphogenesis, KCBP distributes in a specific cortical gradient and concentrates at the branching sites and the apexes of elongating branches, which lack MTs but have cortical F-actin. Further, live-cell imaging and genetic analyses revealed that KCBP acts as a hub integrating MTs and actin filaments to assemble the required cytoskeletal configuration for the unique, polarized diffuse growth pattern during trichome cell morphogenesis. Our findings provide significant insights into the mechanisms underlying cytoskeletal regulation of cell shape determination.
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Affiliation(s)
- Juan Tian
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Libo Han
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zhidi Feng
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Guangda Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Weiwei Liu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yinping Ma
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yanjun Yu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zhaosheng Kong
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
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Direct Microtubule-Binding by Myosin-10 Orients Centrosomes toward Retraction Fibers and Subcortical Actin Clouds. Dev Cell 2015; 34:323-37. [PMID: 26235048 DOI: 10.1016/j.devcel.2015.06.013] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 04/08/2015] [Accepted: 06/12/2015] [Indexed: 11/21/2022]
Abstract
Positioning of centrosomes is vital for cell division and development. In metazoan cells, spindle positioning is controlled by a dynamic pool of subcortical actin that organizes in response to the position of retraction fibers. These actin "clouds" are proposed to generate pulling forces on centrosomes and mediate spindle orientation. However, the motors that pull astral microtubules toward these actin structures are not known. Here, we report that the unconventional myosin, Myo10, couples actin-dependent forces from retraction fibers and subcortical actin clouds to centrosomes. Myo10-mediated centrosome positioning requires its direct microtubule binding. Computational image analysis of large microtubule populations reveals a direct effect of Myo10 on microtubule dynamics and microtubule-cortex interactions. Myo10's role in centrosome positioning is distinct from, but overlaps with, that of dynein. Thus, Myo10 plays a key role in integrating the actin and microtubule cytoskeletons to position centrosomes and mitotic spindles.
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Buschmann H, Dols J, Kopischke S, Peña EJ, Andrade-Navarro MA, Heinlein M, Szymanski DB, Zachgo S, Doonan JH, Lloyd CW. Arabidopsis KCBP interacts with AIR9 but stays in the cortical division zone throughout mitosis via its MyTH4-FERM domain. J Cell Sci 2015; 128:2033-46. [DOI: 10.1242/jcs.156570] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 04/10/2015] [Indexed: 12/19/2022] Open
Abstract
ABSTRACT
The preprophase band of microtubules performs the crucial function of marking the plane of cell division. Although the preprophase band depolymerises at the onset of mitosis, the division plane is ‘memorized’ by a cortical division zone to which the phragmoplast is attracted during cytokinesis. Proteins have been discovered that are part of the molecular memory but little is known about how they contribute to phragmoplast guidance. Previously, we found that the microtubule-associated protein AIR9 is found in the cortical division zone at preprophase and returns during cell plate insertion but is absent from the cortex during the intervening mitosis. To identify new components of the preprophase memory, we searched for proteins that interact with AIR9. We detected the kinesin-like calmodulin-binding protein, KCBP, which can be visualized at the predicted cortical site throughout division. A truncation study of KCBP indicates that its MyTH4-FERM domain is required for linking the motor domain to the cortex. These results suggest a mechanism by which minus-end-directed KCBP helps guide the centrifugally expanding phragmoplast to the cortical division site.
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Affiliation(s)
- Henrik Buschmann
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Jacqueline Dols
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Sarah Kopischke
- Botanical Institute, Biology and Chemistry Department, University of Osnabrück, 49069 Osnabrück, Germany
| | - Eduardo J. Peña
- Institut de Biologie Moléculaire des Plantes, UPR2357 CNRS, Strasbourg, France
| | | | - Manfred Heinlein
- Institut de Biologie Moléculaire des Plantes, UPR2357 CNRS, Strasbourg, France
| | | | - Sabine Zachgo
- Botanical Institute, Biology and Chemistry Department, University of Osnabrück, 49069 Osnabrück, Germany
| | - John H. Doonan
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
| | - Clive W. Lloyd
- Department of Cell and Developmental Biology, John Innes Centre, Norwich, Norfolk NR4 7UH, UK
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Signaling mechanism of the netrin-1 receptor DCC in axon guidance. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 118:153-60. [PMID: 25881791 DOI: 10.1016/j.pbiomolbio.2015.04.001] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Revised: 03/26/2015] [Accepted: 04/05/2015] [Indexed: 12/28/2022]
Abstract
DCC (Deleted in Colorectal Cancer) is a single-pass transmembrane protein that belongs to the immunoglobulin superfamily. It was originally identified as a prognostic tumor marker and then subsequently found to be a receptor for netrin-1. DCC plays a key role in axon guidance and also in a number of other important cellular processes. This review describes the current progress of the structural biology of DCC with an emphasis on how DCC is involved in the dual functionality of netrin-1 as a chemo-attractant as well as a repellent in axon guidance, referred to as bi-functionality. A perspective about other DCC ligands and the signaling mechanism of the cytoplasmic tail of DCC is also recapitulated.
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36
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Abstract
Myosin-X (Myo10) is a motor protein best known for its role in filopodia formation. New research implicates Myo10 in a number of disease states including cancer metastasis and pathogen infection. This review focuses on these developments with emphasis on the emerging roles of Myo10 in formation of cancer cell protrusions and metastasis. A number of aggressive cancers show high levels of Myo10 expression and knockdown of Myo10 has been shown to dramatically limit cancer cell motility in 2D and 3D systems. Myo10 knockdown also limits spread of intracellular pathogens marburgvirus and Shigella flexneri. Consideration is given to how these properties might arise and potential paths of future research.
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Affiliation(s)
- David S Courson
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States
| | - Richard E Cheney
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, United States.
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37
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Wei Z, Li Y, Ye F, Zhang M. Structural basis for the phosphorylation-regulated interaction between the cytoplasmic tail of cell polarity protein crumbs and the actin-binding protein moesin. J Biol Chem 2015; 290:11384-92. [PMID: 25792740 DOI: 10.1074/jbc.m115.643791] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Indexed: 11/06/2022] Open
Abstract
The type I transmembrane protein crumbs (Crb) plays critical roles in the establishment and maintenance of cell polarities in diverse tissues. As such, mutations of Crb can cause different forms of cancers. The cell intrinsic role of Crb in cell polarity is governed by its conserved, 37-residue cytoplasmic tail (Crb-CT) via binding to moesin and protein associated with Lin7-1 (PALS1). However, the detailed mechanism governing the Crb·moesin interaction and the balance of Crb in binding to moesin and PALS1 are not well understood. Here we report the 1.5 Å resolution crystal structure of the moesin protein 4.1/ezrin/radixin/moesin (FERM)·Crb-CT complex, revealing that both the canonical FERM binding motif and the postsynaptic density protein-95/Disc large-1/Zonula occludens-1 (PDZ) binding motif of Crb contribute to the Crb·moesin interaction. We further demonstrate that phosphorylation of Crb-CT by atypical protein kinase C (aPKC) disrupts the Crb·moesin association but has no impact on the Crb·PALS1 interaction. The above results indicate that, upon the establishment of the apical-basal polarity in epithelia, apical-localized aPKC can actively prevent the Crb·moesin complex formation and thereby shift Crb to form complex with PALS1 at apical junctions. Therefore, Crb may serve as an aPKC-mediated sensor in coordinating contact-dependent cell growth inhibition in epithelial tissues.
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Affiliation(s)
- Zhiyi Wei
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and Department of Biology, South University of Science and Technology of China, Shenzhen 518055, China
| | - Youjun Li
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Fei Ye
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and
| | - Mingjie Zhang
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and
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38
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Montague MJ, Li G, Gandolfi B, Khan R, Aken BL, Searle SMJ, Minx P, Hillier LW, Koboldt DC, Davis BW, Driscoll CA, Barr CS, Blackistone K, Quilez J, Lorente-Galdos B, Marques-Bonet T, Alkan C, Thomas GWC, Hahn MW, Menotti-Raymond M, O'Brien SJ, Wilson RK, Lyons LA, Murphy WJ, Warren WC. Comparative analysis of the domestic cat genome reveals genetic signatures underlying feline biology and domestication. Proc Natl Acad Sci U S A 2014; 111:17230-5. [PMID: 25385592 PMCID: PMC4260561 DOI: 10.1073/pnas.1410083111] [Citation(s) in RCA: 198] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Little is known about the genetic changes that distinguish domestic cat populations from their wild progenitors. Here we describe a high-quality domestic cat reference genome assembly and comparative inferences made with other cat breeds, wildcats, and other mammals. Based upon these comparisons, we identified positively selected genes enriched for genes involved in lipid metabolism that underpin adaptations to a hypercarnivorous diet. We also found positive selection signals within genes underlying sensory processes, especially those affecting vision and hearing in the carnivore lineage. We observed an evolutionary tradeoff between functional olfactory and vomeronasal receptor gene repertoires in the cat and dog genomes, with an expansion of the feline chemosensory system for detecting pheromones at the expense of odorant detection. Genomic regions harboring signatures of natural selection that distinguish domestic cats from their wild congeners are enriched in neural crest-related genes associated with behavior and reward in mouse models, as predicted by the domestication syndrome hypothesis. Our description of a previously unidentified allele for the gloving pigmentation pattern found in the Birman breed supports the hypothesis that cat breeds experienced strong selection on specific mutations drawn from random bred populations. Collectively, these findings provide insight into how the process of domestication altered the ancestral wildcat genome and build a resource for future disease mapping and phylogenomic studies across all members of the Felidae.
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Affiliation(s)
- Michael J Montague
- The Genome Institute, Washington University School of Medicine, St. Louis, MO 63108
| | - Gang Li
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843
| | - Barbara Gandolfi
- Department of Veterinary Medicine & Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65201
| | - Razib Khan
- Population Health & Reproduction, School of Veterinary Medicine, University of California, Davis, CA 95616
| | - Bronwen L Aken
- Wellcome Trust Sanger Institute, Hinxton CB10 1SA, United Kingdom
| | | | - Patrick Minx
- The Genome Institute, Washington University School of Medicine, St. Louis, MO 63108
| | - LaDeana W Hillier
- The Genome Institute, Washington University School of Medicine, St. Louis, MO 63108
| | - Daniel C Koboldt
- The Genome Institute, Washington University School of Medicine, St. Louis, MO 63108
| | - Brian W Davis
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843
| | - Carlos A Driscoll
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20886
| | - Christina S Barr
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20886
| | - Kevin Blackistone
- National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20886
| | - Javier Quilez
- Catalan Institution for Research and Advanced Studies, Institute of Evolutionary Biology, Pompeu Fabra University, 08003 Barcelona, Spain
| | - Belen Lorente-Galdos
- Catalan Institution for Research and Advanced Studies, Institute of Evolutionary Biology, Pompeu Fabra University, 08003 Barcelona, Spain
| | - Tomas Marques-Bonet
- Catalan Institution for Research and Advanced Studies, Institute of Evolutionary Biology, Pompeu Fabra University, 08003 Barcelona, Spain; Centro de Analisis Genomico 08028, Barcelona, Spain
| | - Can Alkan
- Department of Computer Engineering, Bilkent University, Ankara 06800, Turkey
| | - Gregg W C Thomas
- Department of Biology, Indiana University, Bloomington, IN 47405
| | - Matthew W Hahn
- Department of Biology, Indiana University, Bloomington, IN 47405
| | | | - Stephen J O'Brien
- Dobzhansky Center for Genome Bioinformatics, St. Petersburg State University, St. Petersburg 199178, Russia; and Oceanographic Center, Nova Southeastern University, Fort Lauderdale, FL 33314
| | - Richard K Wilson
- The Genome Institute, Washington University School of Medicine, St. Louis, MO 63108
| | - Leslie A Lyons
- Department of Veterinary Medicine & Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65201;
| | - William J Murphy
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843;
| | - Wesley C Warren
- The Genome Institute, Washington University School of Medicine, St. Louis, MO 63108;
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Lu Q, Li J, Zhang M. Cargo recognition and cargo-mediated regulation of unconventional myosins. Acc Chem Res 2014; 47:3061-70. [PMID: 25230296 DOI: 10.1021/ar500216z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Organized motions are hallmarks of living organisms. Such motions range from collective cell movements during development and muscle contractions at the macroscopic scale all the way down to cellular cargo (e.g., various biomolecules and organelles) transportation and mechanoforce sensing at more microscopic scales. Energy required for these biological motions is almost invariably provided by cellular chemical fuels in the form of nucleotide triphosphate. Biological systems have designed a group of nanoscale engines, known as molecular motors, to convert cellular chemical fuels into mechanical energy. Molecular motors come in various forms including cytoskeleton motors (myosin, kinesin, and dynein), nucleic-acid-based motors, cellular membrane-based rotary motors, and so on. The main focus of this Account is one subfamily of actin filament-based motors called unconventional myosins (other than muscle myosin II, the remaining myosins are collectively referred to as unconventional myosins). In general, myosins can use ATP to fuel two types of mechanomotions: dynamic tethering actin filaments with various cellular compartments or structures and actin filament-based intracellular transport. In contrast to rich knowledge accumulated over many decades on ATP hydrolyzing motor heads and their interactions with actin filaments, how various myosins recognize their specific cargoes and whether and how cargoes can in return regulate functions of motors are less understood. Nonetheless, a series of biochemical and structural investigations in the past few years, including works from our own laboratory, begin to shed lights on these latter questions. Some myosins (e.g., myosin-VI) can function both as cellular transporters and as mechanical tethers. To function as a processive transporter, myosins need to form dimers or multimers. To be a mechanical tether, a monomeric myosin is sufficient. It has been shown for myosin-VI that its cellular cargo proteins can play critical roles in determining the motor properties. Dab2, an adaptor protein linking endocytic vesicles with actin-filament-bound myosin-VI, can induce the motor to form a transport competent dimer. Such a cargo-mediated dimerization mechanism has also been observed in other myosins including myosin-V and myosin-VIIa. The tail domains of myosins are very diverse both in their lengths and protein domain compositions and thus enable motors to engage a broad range of different cellular cargoes. Remarkably, the cargo binding tail of one myosin alone often can bind to multiple distinct target proteins. A series of atomic structures of myosin-V/cargo complexes solved recently reveals that the globular cargo binding tail of the motor contains a number of nonoverlapping target recognition sites for binding to its cargoes including melanophilin, vesicle adaptors RILPL2, and vesicle-bound GTPase Rab11. The structures of the MyTH4-FERM tandems from myosin-VIIa and myosin-X in complex with their respective targets reveal that MyTH4 and FERM domains extensively interact with each other forming structural and functional supramodules in both motors and demonstrate that the structurally similar MyTH4-FERM tandems of the two motors display totally different target binding modes. These structural studies have also shed light on why numerous mutations found in these myosins can cause devastating human diseases such as deafness and blindness, intellectual disabilities, immune disorders, and diabetes.
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Affiliation(s)
- Qing Lu
- Division
of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
| | - Jianchao Li
- Division
of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
| | - Mingjie Zhang
- Division
of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
- Center of Systems Biology and Human Health, School of
Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong China
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40
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Winkle CC, McClain LM, Valtschanoff JG, Park CS, Maglione C, Gupton SL. A novel Netrin-1-sensitive mechanism promotes local SNARE-mediated exocytosis during axon branching. ACTA ACUST UNITED AC 2014; 205:217-32. [PMID: 24778312 PMCID: PMC4003241 DOI: 10.1083/jcb.201311003] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Localized plasma membrane expansion during axon branching mediated by Netrin-1 occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion. Developmental axon branching dramatically increases synaptic capacity and neuronal surface area. Netrin-1 promotes branching and synaptogenesis, but the mechanism by which Netrin-1 stimulates plasma membrane expansion is unknown. We demonstrate that SNARE-mediated exocytosis is a prerequisite for axon branching and identify the E3 ubiquitin ligase TRIM9 as a critical catalytic link between Netrin-1 and exocytic SNARE machinery in murine cortical neurons. TRIM9 ligase activity promotes SNARE-mediated vesicle fusion and axon branching in a Netrin-dependent manner. We identified a direct interaction between TRIM9 and the Netrin-1 receptor DCC as well as a Netrin-1–sensitive interaction between TRIM9 and the SNARE component SNAP25. The interaction with SNAP25 negatively regulates SNARE-mediated exocytosis and axon branching in the absence of Netrin-1. Deletion of TRIM9 elevated exocytosis in vitro and increased axon branching in vitro and in vivo. Our data provide a novel model for the spatial regulation of axon branching by Netrin-1, in which localized plasma membrane expansion occurs via TRIM9-dependent regulation of SNARE-mediated vesicle fusion.
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Affiliation(s)
- Cortney C Winkle
- Neuroscience Center and Curriculum in Neurobiology, 2 Department of Cell Biology and Physiology, and 3 Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
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41
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Li Y, Wei Z, Zhang J, Yang Z, Zhang M. Structural basis of the binding of Merlin FERM domain to the E3 ubiquitin ligase substrate adaptor DCAF1. J Biol Chem 2014; 289:14674-81. [PMID: 24706749 DOI: 10.1074/jbc.m114.551184] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The tumor suppressor gene Nf2 product, Merlin, plays vital roles in controlling proper development of organ sizes by specifically binding to a large number of target proteins localized both in cytoplasm and nuclei. The FERM domain of Merlin is chiefly responsible for its binding to target proteins, although the molecular basis governing these interactions are poorly understood due to lack of structural information. Here, we report the crystal structure of the Merlin FERM domain in complex with its binding domain derived from the E3 ubiquitin ligase substrate adaptor DCAF1 (also known as VPRBP). Unlike target binding modes found in ERM proteins, the Merlin-FERM binding domain of DCAF1 folds as a β-hairpin and binds to the α1/β5-groove of the F3 lobe of Merlin-FERM via extensive hydrophobic interactions. In addition to providing the first structural glimpse of a Merlin-FERM·target complex, the structure of the Merlin·DCAF1 complex is likely to be valuable for understanding the interactions of Merlin with its binding partners other than DCAF1.
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Affiliation(s)
- Youjun Li
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Zhiyi Wei
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, the Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and the Department of Biology, South University of Science and Technology of China, Shenzhen, China
| | - Junyi Zhang
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Zhou Yang
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- From the Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, the Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and
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Lin WH, Hurley JT, Raines AN, Cheney RE, Webb DJ. Myosin X and its motorless isoform differentially modulate dendritic spine development by regulating trafficking and retention of vasodilator-stimulated phosphoprotein. J Cell Sci 2013; 126:4756-68. [PMID: 23943878 DOI: 10.1242/jcs.132969] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Myosin X (Myo10) is an unconventional myosin with two known isoforms: full-length (FL)-Myo10 that has motor activity, and a recently identified brain-expressed isoform, headless (Hdl)-Myo10, which lacks most of the motor domain. FL-Myo10 is involved in the regulation of filopodia formation in non-neuronal cells; however, the biological function of Hdl-Myo10 remains largely unknown. Here, we show that FL- and Hdl-Myo10 have important, but distinct, roles in the development of dendritic spines and synapses in hippocampal neurons. FL-Myo10 induces formation of dendritic filopodia and modulates filopodia dynamics by trafficking the actin-binding protein vasodilator-stimulated phosphoprotein (VASP) to the tips of filopodia. By contrast, Hdl-Myo10 acts on dendritic spines to enhance spine and synaptic density as well as spine head expansion by increasing the retention of VASP in spines. Thus, this study demonstrates a novel biological function for Hdl-Myo10 and an important new role for both Myo10 isoforms in the development of dendritic spines and synapses.
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Affiliation(s)
- Wan-Hsin Lin
- Department of Biological Sciences and Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tennessee 37235, USA
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Gousset K, Marzo L, Commere PH, Zurzolo C. Myo10 is a key regulator of TNT formation in neuronal cells. J Cell Sci 2013; 126:4424-35. [PMID: 23886947 DOI: 10.1242/jcs.129239] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cell-to-cell communication is essential in multicellular organisms. Tunneling nanotubes (TNTs) have emerged as a new type of intercellular spreading mechanism allowing the transport of various signals, organelles and pathogens. Here, we study the role of the unconventional molecular motor myosin-X (Myo10) in the formation of functional TNTs within neuronal CAD cells. Myo10 protein expression increases the number of TNTs and the transfer of vesicles between co-cultured cells. We also show that TNT formation requires both the motor and tail domains of the protein, and identify the F2 lobe of the FERM domain within the Myo10 tail as necessary for TNT formation. Taken together, these results indicate that, in neuronal cells, TNTs can arise from a subset of Myo10-driven dorsal filopodia, independent of its binding to integrins and N-cadherins. In addition our data highlight the existence of different mechanisms for the establishment and regulation of TNTs in neuronal cells and other cell types.
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Affiliation(s)
- Karine Gousset
- Institut Pasteur, 25 Rue du Dr Roux, Unité de Traffic Membranaire et Pathogenèse, 75724 Paris Cedex 15, France
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Ju XD, Guo Y, Wang NN, Huang Y, Lai MM, Zhai YH, Guo YG, Zhang JH, Cao RJ, Yu HL, Cui L, Li YT, Wang XZ, Ding YQ, Zhu XJ. Both Myosin-10 isoforms are required for radial neuronal migration in the developing cerebral cortex. ACTA ACUST UNITED AC 2013; 24:1259-68. [PMID: 23300110 DOI: 10.1093/cercor/bhs407] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
During embryonic development of the mammalian cerebral cortex, postmitotic cortical neurons migrate radially from the ventricular zone to the cortical plate. Proper migration involves the correct orientation of migrating neurons and the transition from a multipolar to a mature bipolar morphology. Herein, we report that the 2 isoforms of Myosin-10 (Myo10) play distinct roles in the regulation of radial migration in the mouse cortex. We show that the full-length Myo10 (fMyo10) isoform is located in deeper layers of the cortex and is involved in establishing proper migration orientation. We also demonstrate that fMyo10-dependent orientation of radial migration is mediated at least in part by the netrin-1 receptor deleted in colorectal cancer. Moreover, we show that the headless Myo10 (hMyo10) isoform is required for the transition from multipolar to bipolar morphologies in the intermediate zone. Our study reveals divergent functions for the 2 Myo10 isoforms in controlling both the direction of migration and neuronal morphogenesis during radial cortical neuronal migration.
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Affiliation(s)
- Xing-Da Ju
- Key Laboratory of Molecular Epigenetics, Ministry of Education, Institute of Genetics and Cytology, Northeast Normal University, Changchun 130021, China
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Bishai EA, Sidhu GS, Li W, Dhillon J, Bohil AB, Cheney RE, Hartwig JH, Southwick FS. Myosin-X facilitates Shigella-induced membrane protrusions and cell-to-cell spread. Cell Microbiol 2012; 15:353-367. [PMID: 23083060 DOI: 10.1111/cmi.12051] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Revised: 09/25/2012] [Accepted: 10/08/2012] [Indexed: 11/29/2022]
Abstract
The intracellular pathogen Shigella flexneri forms membrane protrusions to spread from cell to cell. As protrusions form, myosin-X (Myo10) localizes to Shigella. Electron micrographs of immunogold-labelled Shigella-infected HeLa cells reveal that Myo10 concentrates at the bases and along the sides of bacteria within membrane protrusions. Time-lapse video microscopy shows that a full-length Myo10 GFP-construct cycles along the sides of Shigella within the membrane protrusions as these structures progressively lengthen. RNAi knock-down of Myo10 is associated with shorter protrusions with thicker stalks, and causes a >80% decrease in confluent cell plaque formation. Myo10 also concentrates in membrane protrusions formed by another intracellular bacteria, Listeria, and knock-down of Myo10 also impairs Listeria plaque formation. In Cos7 cells (contain low concentrations of Myo10), the expression of full-length Myo10 nearly doubles Shigella-induced protrusion length, and lengthening requires the head domain, as well as the tail-PH domain, but not the FERM domain. The GFP-Myo10-HMM domain localizes to the sides of Shigella within membrane protrusions and the GFP-Myo10-PH domain localizes to host cell membranes. We conclude thatMyo10 generates the force to enhance bacterial-induced protrusions by binding its head region to actin filaments and its PH tail domain to the peripheral membrane.
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Affiliation(s)
- Ellen A Bishai
- Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA
| | - Gurjit S Sidhu
- Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA
| | - Wei Li
- Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jess Dhillon
- Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA
| | - Aparna B Bohil
- Department of Cell and Molecular Physiology, University of North Carolina, Chapel Hill, NC, USA
| | - Richard E Cheney
- Department of Cell and Molecular Physiology, University of North Carolina, Chapel Hill, NC, USA
| | - John H Hartwig
- Department of Medicine, Division of Translational Medicine, Brigham and Women's Hospital, Harvard University, Boston, MA, USA
| | - Frederick S Southwick
- Department of Medicine, Division of Infectious Diseases, University of Florida College of Medicine, Gainesville, FL, USA
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Abstract
Processive movements of unconventional myosins on actin filaments generally require motor dimerization. A commonly accepted myosin dimerization mechanism is via formation of a parallel coiled-coil dimer by a stretch of amino acid residues immediately carboxyl-terminal to the motor's lever-arm domain. Here, we discover that the predicted coiled-coil region of myosin X forms a highly stable, antiparallel coiled-coil dimer (anti-CC). Disruption of the anti-CC either by single-point mutations or by replacement of the anti-CC with a parallel coiled coil with a similar length compromised the filopodial induction activity of myosin X. We further show that the anti-CC and the single α-helical domain of myosin X are connected by a semirigid helical linker. The anti-CC-mediated dimerization may enable myosin X to walk on both single and bundled actin filaments.
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Perisic L, Lal M, Hulkko J, Hultenby K, Önfelt B, Sun Y, Dunér F, Patrakka J, Betsholtz C, Uhlen M, Brismar H, Tryggvason K, Wernerson A, Pikkarainen T. Plekhh2, a novel podocyte protein downregulated in human focal segmental glomerulosclerosis, is involved in matrix adhesion and actin dynamics. Kidney Int 2012; 82:1071-83. [PMID: 22832517 DOI: 10.1038/ki.2012.252] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Pleckstrin homology domain-containing, family H (with MyTH4 domain), member 2 (Plekhh2) is a 1491-residue intracellular protein highly enriched in renal glomerular podocytes for which no function has been ascribed. Analysis of renal biopsies from patients with focal segmental glomerulosclerosis revealed a significant reduction in total podocyte Plekhh2 expression compared to controls. Sequence analysis indicated a putative α-helical coiled-coil segment as the only recognizable domain within the N-terminal half of the polypeptide, while the C-terminal half contains two PH, a MyTH4, and a FERM domain. We identified a phosphatidylinositol-3-phosphate consensus-binding site in the PH1 domain required for Plekhh2 localization to peripheral regions of cell lamellipodia. The N-terminal half of Plekkh2 is not necessary for lamellipodial targeting but mediates self-association. Yeast two-hybrid screening showed that Plekhh2 directly interacts through its FERM domain with the focal adhesion protein Hic-5 and actin. Plekhh2 and Hic-5 coprecipitated and colocalized at the soles of podocyte foot processes in situ and Hic-5 partially relocated from focal adhesions to lamellipodia in Plekhh2-expressing podocytes. In addition, Plekhh2 stabilizes the cortical actin cytoskeleton by attenuating actin depolymerization. Our findings suggest a structural and functional role for Plekhh2 in the podocyte foot processes.
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Affiliation(s)
- Ljubica Perisic
- Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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Raines AN, Nagdas S, Kerber ML, Cheney RE. Headless Myo10 is a negative regulator of full-length Myo10 and inhibits axon outgrowth in cortical neurons. J Biol Chem 2012; 287:24873-83. [PMID: 22661706 DOI: 10.1074/jbc.m112.369173] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Myo10 is an unconventional myosin that localizes to and induces filopodia, structures that are critical for growing axons. In addition to the ~240-kDa full-length Myo10, brain expresses a ~165 kDa isoform that lacks a functional motor domain and is known as headless Myo10. We and others have hypothesized that headless Myo10 acts as an endogenous dominant negative of full-length Myo10, but this hypothesis has not been tested, and the function of headless Myo10 remains unknown. We find that cortical neurons express both headless and full-length Myo10 and report the first isoform-specific localization of Myo10 in brain, which shows enrichment of headless Myo10 in regions of proliferating and migrating cells, including the embryonic ventricular zone and the postnatal rostral migratory stream. We also find that headless and full-length Myo10 are expressed in embryonic and neuronal stem cells. To directly test the function of headless and full-length Myo10, we used RNAi specific to each isoform in mouse cortical neuron cultures. Knockdown of full-length Myo10 reduces axon outgrowth, whereas knockdown of headless Myo10 increases axon outgrowth. To test whether headless Myo10 antagonizes full-length Myo10, we coexpressed both isoforms in COS-7 cells, which revealed that headless Myo10 suppresses the filopodia-inducing activity of full-length Myo10. Together, these results demonstrate that headless Myo10 can function as a negative regulator of full-length Myo10 and that the two isoforms of Myo10 have opposing roles in axon outgrowth.
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Affiliation(s)
- Alexander N Raines
- Curriculum in Neurobiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Pan L, Zhang M. Structures of usher syndrome 1 proteins and their complexes. Physiology (Bethesda) 2012; 27:25-42. [PMID: 22311968 DOI: 10.1152/physiol.00037.2011] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Usher syndrome 1 (USH1) is the most common and severe form of hereditary loss of hearing and vision. Genetic, physiological, and cell biological studies, together with recent structural investigations, have not only uncovered the physiological functions of the five USH1 proteins but also provided mechanistic explanations for the hearing and visual deficiencies in humans caused by USH1 mutations. This review focuses on the structural basis of the USH1 protein complex organization.
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Affiliation(s)
- Lifeng Pan
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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50
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Abstract
Myosin-X (Myo10) is an unconventional myosin with MyTH4-FERM domains that is best known for its striking localization to the tips of filopodia and its ability to induce filopodia. Although the head domain of Myo10 enables it to function as an actin-based motor, its tail contains binding sites for several molecules with central roles in cell biology, including phosphatidylinositol (3,4,5)-trisphosphate, microtubules and integrins. Myo10 also undergoes fascinating long-range movements within filopodia, which appear to represent a newly recognized system of transport. Myo10 is also unusual in that it is a myosin with important roles in the spindle, a microtubule-based structure. Exciting new studies have begun to reveal the structure and single-molecule properties of this intriguing myosin, as well as its mechanisms of regulation and induction of filopodia. At the cellular and organismal level, growing evidence demonstrates that Myo10 has crucial functions in numerous processes ranging from invadopodia formation to cell migration.
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Affiliation(s)
- Michael L Kerber
- Department of Cell and Molecular Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7545, USA
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