The studies detailed in this proposal seek to understand myosin-1 interactions with membranes and membrane components at the molecular level and to elucidate the role of these interactions in membrane organization and dynamics. Myosin-1 family members (eight different genes expressed in humans) are single-headed motor proteins that play essential roles in membrane dynamics and other cellular processes. A key property of myosin-1 isoforms appears to be their ability to directly link the actin cytoskeleton to cell membranes. Several myosin-1 isoforms have been shown to bind directly to membranes, and one isoform, myo1c, has been shown to bind tightly to phosphoinositide headgroups via a putative pleckstrin homology domain in its tail domain. Given the importance on the myosin-1 family in driving membrane dynamics, it is remarkable that the membrane interactions of most of the myosin-1 have been unexplored. Therefore, this proposal is focused on characterizing the myosin-1-membrane interactions. We will use a variety of biochemical and biophysical techniques to examine membrane binding specificities, affinities, and dynamics.
The specific aims are as follows:
Aim 1 : Binding of myosin-1 family members to membranes and phosphoinositides Subaim 1.1: Characterization of phosphoinositide binding Subaim 1.2: Phosphoinositide specificity Subaim 1.3: Kinetics of binding Aim 2: Interplay between membranes and the actomyosin system Subaim 2.1 Reconstitution of actin motility on membrane surfaces Subaim 2.2 Myosin-mediated PIP2 clustering Subaim 2.3 Dynamics of myosin-1 binding to PIP2 in a membrane.

Public Health Relevance

Myosin-1 family members are important for numerous basic cellular processes. In humans, myosin-1 mutations have been linked to deafness, while myosin-1 deletions in mice result in increased susceptibility to infection, kidney inflammation, and defects in the gut endothelium. Understanding the specificity of and roles for myosin-1 interactions with lipid components of the cell membrane will provide insight into these normal and diseased physiological states.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM090551-02
Application #
8048021
Study Section
Special Emphasis Panel (ZRG1-F04B-B (20))
Program Officer
Sakalian, Michael
Project Start
2010-02-01
Project End
2013-01-31
Budget Start
2011-02-01
Budget End
2012-01-31
Support Year
2
Fiscal Year
2011
Total Cost
$51,326
Indirect Cost
Name
University of Pennsylvania
Department
Physiology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Zwolak, Adam; Yang, Changsong; Feeser, Elizabeth A et al. (2013) CARMIL leading edge localization depends on a non-canonical PH domain and dimerization. Nat Commun 4:2523
Feeser, Elizabeth A; Ignacio, Cherry Mae G; Krendel, Mira et al. (2010) Myo1e binds anionic phospholipids with high affinity. Biochemistry 49:9353-60