Regulation of Myosin V-Cargo Interactions by Phosphorylation

Roland, Joseph Thomas Edward

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Description

Title

Regulation of Myosin V-Cargo Interactions by Phosphorylation

Author(s)

Roland, Joseph Thomas Edward

Issue Date

2004

Doctoral Committee Chair(s)

Vladimir I. Gelfand

Department of Study

Microbiology

Discipline

Microbiology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Biology, Cell

Language

eng

Abstract

Myosin V is required for the proper transport and localization of specific organelles along actin filaments in many cell types. Two independent kinases, Calcium/calmodulin-dependent kinase II (CaMKII) and p21-activated kinase-1 (PAK1), are able to phosphorylate the globular tail of myosin V. Mutation analysis and mass spectrometry were used to determine the actual site of phosphorylation for each kinase. The target of CaMKII phosphorylation is the serine residue at position 1650 in the globular tail of mouse myosin Va, while PAK1 phosphorylates the serine residue located at position 1649. The tandem localization of these two, independent phosphorylation sites suggests that this region of the protein is central to motor regulation. During mitosis, CaMKII phosphorylation of myosin V inhibits the ability of the motor to bind to Xenopus melanosomes. Similarly, myosin V recruitment to mouse phagosomes during phagocytosis is blocked by PAK1 phosphorylation. Thus, the binding of myosin V to cargo is regulated by phosphorylation of the tail domain, and may represent a common mechanism of regulation of vertebrate myosin V.

Graduation Semester

2004

Type of Resource

text

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