Myosin-1a is critical for normal brush border structure and composition

Matthew J. Tyska, Andrew T. Mackey, Jian Dong Huang, Neil G. Copeland, Nancy A. Jenkins, Mark S. Mooseker

Research output: Contribution to journalArticlepeer-review

153 Scopus citations


To develop our understanding of myosin-1a function in vivo, we have created a mouse line null for the myosin-1a gene. Myosin-1a knockout mice demonstrate no overt phenotypes at the whole animal level but exhibit significant perturbations and signs of stress at the cellular level. Among these are defects in microvillar membrane morphology, distinct changes in brush-border organization, loss of numerous cytoskeletal and membrane components from the brush border, and redistribution of intermediate filament proteins into the brush border. We also observed significant ectopic recruitment of another short-tailed class I motor, myosin-1c, into the brush border of knockout enterocytes. This latter finding, a clear demonstration of functional redundancy among vertebrate myosins-I, may account for the lack of a whole animal phenotype. Nevertheless, these results indicate that myosin-1a is a critical multifunctional component of the enterocyte, required for maintaining the normal composition and highly ordered structure of the brush border.

Original languageEnglish (US)
Pages (from-to)2443-2457
Number of pages15
JournalMolecular Biology of the Cell
Issue number5
StatePublished - May 2005

ASJC Scopus subject areas

  • Molecular Biology
  • Cell Biology


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