Intermolecular autophosphorylation regulates myosin IIIa activity and localization in parallel actin bundles

Omar A. Quintero, Judy E. Moore, William C. Unrath, Uri Manor, Felipe T. Salles, M'Hamed Grati, Bechara Kachar, Christopher M. Yengo

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

Myosin IIIa (Myo3A) transports cargo to the distal end of actin protrusions and contains a kinase domain that is thought to autoregulate its activity. Because Myo3A tends to cluster at the tips of actin protrusions, we investigated whether intermolecular phosphorylation could regulate Myo3A biochemical activity, cellular localization, and cellular function. Inactivation of Myo3A 2IQ kinase domain with the point mutation K50R did not alter maximal ATPase activity, whereas phosphorylation of Myo3A 2IQ resulted in reduced maximal ATPase activity and actin affinity. The rate and degree of Myo3A 2IQ autophosphorylation was unchanged by the presence of actin but was found to be dependent upon Myo3A 2IQ concentration within the range of 0.1 to 1.2 μM, indicating intermolecular autophosphorylation. In cultured cells, we observed that the filopodial tip localization of Myo3A lacking the kinase domain decreased when co-expressed with kinase-active, full-length Myo3A. The cellular consequence of reduced Myo3A tip localization was decreased filopodial density along the cell periphery, identifying a novel cellular function for Myo3A in mediating the formation and stability of actin-based protrusions. Our results suggest that Myo3A motor activity is regulated through a mechanism involving concentration-dependent autophosphorylation. We suggest that this regulatory mechanism plays an essential role in mediating the transport and actin bundle formation/stability functions of Myo3A.

Original languageEnglish (US)
Pages (from-to)35770-35782
Number of pages13
JournalJournal of Biological Chemistry
Volume285
Issue number46
DOIs
StatePublished - Nov 12 2010
Externally publishedYes

Fingerprint

Myosins
Actins
Phosphotransferases
Phosphorylation
Adenosine Triphosphatases
Point Mutation
Cultured Cells
Motor Activity
Cell Count
Cells

ASJC Scopus subject areas

  • Biochemistry
  • Cell Biology
  • Molecular Biology

Cite this

Quintero, O. A., Moore, J. E., Unrath, W. C., Manor, U., Salles, F. T., Grati, MH., ... Yengo, C. M. (2010). Intermolecular autophosphorylation regulates myosin IIIa activity and localization in parallel actin bundles. Journal of Biological Chemistry, 285(46), 35770-35782. https://doi.org/10.1074/jbc.M110.144360

Intermolecular autophosphorylation regulates myosin IIIa activity and localization in parallel actin bundles. / Quintero, Omar A.; Moore, Judy E.; Unrath, William C.; Manor, Uri; Salles, Felipe T.; Grati, M'Hamed; Kachar, Bechara; Yengo, Christopher M.

In: Journal of Biological Chemistry, Vol. 285, No. 46, 12.11.2010, p. 35770-35782.

Research output: Contribution to journalArticle

Quintero, OA, Moore, JE, Unrath, WC, Manor, U, Salles, FT, Grati, MH, Kachar, B & Yengo, CM 2010, 'Intermolecular autophosphorylation regulates myosin IIIa activity and localization in parallel actin bundles', Journal of Biological Chemistry, vol. 285, no. 46, pp. 35770-35782. https://doi.org/10.1074/jbc.M110.144360
Quintero, Omar A. ; Moore, Judy E. ; Unrath, William C. ; Manor, Uri ; Salles, Felipe T. ; Grati, M'Hamed ; Kachar, Bechara ; Yengo, Christopher M. / Intermolecular autophosphorylation regulates myosin IIIa activity and localization in parallel actin bundles. In: Journal of Biological Chemistry. 2010 ; Vol. 285, No. 46. pp. 35770-35782.
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