Mechanism, regulation, and functional properties of Dictyostelium myosin-1B

Tsiavaliaris, G. and Fujita-Becker, S. and Durrwang, U. and Diensthuber, R.P. and Geeves, M.A. and Manstein, D.J. (2008) Mechanism, regulation, and functional properties of Dictyostelium myosin-1B. Journal of Biological Chemistry, 283 (8). pp. 4520-4527. ISSN 0021-9258. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1074/jbc.M708113200

Abstract

Myosin-1B is one of three long tailed class-1 myosins containing an ATP-insensitive actin-binding site in the tail region that are produced in Dictyostelium discoideum. Myosin-1B localizes to actin-rich structures at the leading edge of migrating cells where it has been implicated in the formation and retraction of membrane projections, the recycling of plasma membrane components, and intracellular particle transport. Here, we have used a combination of molecular engineering approaches to describe the kinetic and motile properties of the myosin-1B motor and its regulation by TEDS site phosphorylation. Our results show that myosin-1B is a low duty ratio motor and displays the fastest nucleotide binding kinetics of any of the Dictyostelium class-1 myosins studied so far. Different from Dictyostelium myosin-1D and myosin-1E, dephosphorylated myosin-1B is not inactivated but moves actin filaments efficiently, albeit at an up to 8-fold slower velocity in the in vitro motility assay. A further difference is that myosin-1B lacks the ability to switch between rapid movement and bearing tension upon physiological changes of free Mg2+ ions. In this respect, its motor properties appear to be more closely related to Dictyostelium myosin-2 and rabbit skeletal muscle myosin.

Item Type: Article
Additional information: 070021/United Kingdom Wellcome Trust Journal Article Research Support, Non-U.S. Gov't United States
Uncontrolled keywords: Actins/genetics/*metabolism Animals Binding Sites/genetics Biological Transport/physiology Cell Surface Extensions/genetics/*metabolism Dictyostelium/cytology/genetics/*metabolism Kinetics Magnesium/metabolism Microfilaments/genetics/*metabolism Myosins/genetics/*metabolism Nucleotides/metabolism Protein Binding/physiology Protozoan Proteins/genetics/*metabolism Rabbits Species Specificity
Subjects: Q Science > Q Science (General)
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences > Protein Science Group
Depositing User: Louise Dorman
Date Deposited: 28 Apr 2009 13:49
Last Modified: 15 May 2009 12:24
Resource URI: http://kar.kent.ac.uk/id/eprint/15272 (The current URI for this page, for reference purposes)
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