# Class I myosins regulate protrusive forces at the actin-membrane interface

> **NIH NIH R01** · UPSTATE MEDICAL UNIVERSITY · 2024 · $534,028

## Abstract

In this project, we will dissect the roles of class I myosins, molecular motors that bind actin
filaments through their motor domains and plasma membrane through their tail domains, in
actin-mediated cell shape changes. We will test the hypothesis that myosin I motor activity
promotes assembly of branched actin networks at the sites of membrane deformation, including
endocytic vesicles, phagocytic cups, and podosomes. The proposed work will use two model
systems: fission yeast, where myosin I is required for endocytosis, and murine macrophages,
which rely on myosin I for phagocytosis and cell migration. In aim 1, we will determine how
myosin motor activity contributes to endocytic actin patch assembly and internalization in yeast.
We will use the genetically tractable yeast system to express mutant myosin from the
endogenous myosin locus and apply molecule counting techniques, which are well established
in the yeast endocytosis system, to measure the rates of actin assembly. In aim 2, we will test
the role of myosin motor activity in actin and membrane dynamics during phagocytosis and cell
migration. These studies will take advantage of the genetically modified mice lacking class I
myosins that are available in our labs. In aim 3, we will determine how myosin-membrane
interactions are regulated to contribute to myosin functions in actin assembly and immune
response. The proposed work will shed light on the molecular mechanisms driving actin-
dependent membrane deformation.

## Key facts

- **NIH application ID:** 10835903
- **Project number:** 5R01GM138652-04
- **Recipient organization:** UPSTATE MEDICAL UNIVERSITY
- **Principal Investigator:** Mira Krendel
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $534,028
- **Award type:** 5
- **Project period:** 2021-07-06 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10835903

## Citation

> US National Institutes of Health, RePORTER application 10835903, Class I myosins regulate protrusive forces at the actin-membrane interface (5R01GM138652-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10835903. Licensed CC0.

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