NDLI: Functions of Nonmuscle Myosin II in Assembly of the Cellular Contractile System

Content Provider	PubMed Central
Author	Shutova, Maria Yang, Changsong Vasiliev, Jury M. Svitkina, Tatyana
Editor	Parsons, Maddy
Copyright Year	2012
Abstract	The contractile system of nonmuscle cells consists of interconnected actomyosin networks and bundles anchored to focal adhesions. The initiation of the contractile system assembly is poorly understood structurally and mechanistically, whereas system’s maturation heavily depends on nonmuscle myosin II (NMII). Using platinum replica electron microscopy in combination with fluorescence microscopy, we characterized the structural mechanisms of the contractile system assembly and roles of NMII at early stages of this process. We show that inhibition of NMII by a specific inhibitor, blebbistatin, in addition to known effects, such as disassembly of stress fibers and mature focal adhesions, also causes transformation of lamellipodia into unattached ruffles, loss of immature focal complexes, loss of cytoskeleton-associated NMII filaments and peripheral accumulation of activated, but unpolymerized NMII. After blebbistatin washout, assembly of the contractile system begins with quick and coordinated recovery of lamellipodia and focal complexes that occurs before reappearance of NMII bipolar filaments. The initial formation of focal complexes and subsequent assembly of NMII filaments preferentially occurred in association with filopodial bundles and concave actin bundles formed by filopodial roots at the lamellipodial base. Over time, accumulating NMII filaments help to transform the precursor structures, focal complexes and associated thin bundles, into stress fibers and mature focal adhesions. However, semi-sarcomeric organization of stress fibers develops at much slower rate. Together, our data suggest that activation of NMII motor activity by light chain phosphorylation occurs at the cell edge and is uncoupled from NMII assembly into bipolar filaments. We propose that activated, but unpolymerized NMII initiates focal complexes, thus providing traction for lamellipodial protrusion. Subsequently, the mechanical resistance of focal complexes activates a load-dependent mechanism of NMII polymerization in association with attached bundles, leading to assembly of stress fibers and maturation of focal adhesions.
Related Links	http://dx.doi.org/10.1371/journal.pone.0040814
Starting Page	40814
File Format	PDF
ISSN	19326203
e-ISSN	19326203
Journal	PLoS ONE
Issue Number	7
Volume Number	7
Language	English
Publisher	Public Library of Science
Publisher Date	2012-07-01
Access Restriction	Open
Rights Holder	Public Library of Science
Subject Keyword	Biochemistry, Genetics and Molecular Biology(all) Agricultural and Biological Sciences(all) Medicine(all) Research in Higher Education
Content Type	Text
Resource Type	Article
Subject	Multidisciplinary

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Temporal control of contractile ring assembly by Plo1 regulation of Myosin II recruitment by Mid1/Anillin

The Functions of Myosin II and Myosin V Homologs in Tip Growth and Septation in Aspergillus nidulans

Ultraslow Myosin Molecular Motors of Placental Contractile Stem Villi in Humans

Myosin II Motor Proteins with Different Functions Determine the Fate of Lamellipodia Extension during Cell Spreading

Endogenous species of mammalian nonmuscle myosin IIA and IIB include activated monomers and heteropolymers

Redistribution of Actin during Assembly and Reassembly of the Contractile Ring in Grasshopper Spermatocytes

A New Role for Myosin II in Vesicle Fission

The Prp19 Complex Directly Functions in Mitotic Spindle Assembly

RhoA GTPase Switch Controls Cx43-Hemichannel Activity through the Contractile System

Functions of Nonmuscle Myosin II in Assembly of the Cellular Contractile System

Similar Documents

Temporal control of contractile ring assembly by Plo1 regulation of Myosin II recruitment by Mid1/Anillin

The Functions of Myosin II and Myosin V Homologs in Tip Growth and Septation in Aspergillus nidulans

Ultraslow Myosin Molecular Motors of Placental Contractile Stem Villi in Humans

Myosin II Motor Proteins with Different Functions Determine the Fate of Lamellipodia Extension during Cell Spreading

Endogenous species of mammalian nonmuscle myosin IIA and IIB include activated monomers and heteropolymers

Redistribution of Actin during Assembly and Reassembly of the Contractile Ring in Grasshopper Spermatocytes

A New Role for Myosin II in Vesicle Fission

The Prp19 Complex Directly Functions in Mitotic Spindle Assembly

RhoA GTPase Switch Controls Cx43-Hemichannel Activity through the Contractile System

Functions of Nonmuscle Myosin II in Assembly of the Cellular Contractile System