A single class II myosin modulates T cell motility and stopping, but not synapse formation.
Upon encountering an antigen, motile T cells stop crawling, change morphology and ultimately form an 'immunological synapse'. Although myosin motors are thought to mediate various aspects of this process, the molecules involved and their exact roles are not defined. Here we show that nonmuscle myosin heavy chain IIA, or MyH9, is the only class II myosin expressed in T cells and is associated with the uropod during crawling. MyH9 function is required for maintenance of the uropod and for T cell motility but is dispensable for synapse formation. Phosphorylation of MyH9 in its multimerization domain by T cell receptor-generated signals indicates that inactivation of this motor may be a key step in the 'stop' response during antigen recognition.
Jacobelli
Jordan
J
Department of Pathology, University of California at San Francisco, 513 Parnassus Ave., San Francisco, California 93143, USA.
Chmura
Stephen A
SA
Buxton
Denis B
DB
Davis
Mark M
MM
Krummel
Matthew F
MF
D000818:Animals; D002465:Cell Movement / Q000502:physiology*; D051379:Mice; D020409:Molecular Motor Proteins / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000378:metabolism*; D010766:Phosphorylation; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*
D020409:Molecular Motor Proteins; D011948:Receptors, Antigen, T-Cell; D018995:Myosin Heavy Chains