title: PAR-1/MARK: a kinase essential for maintaining the dynamic state of microtubules.
abstract: The serine/threonine kinase, PAR-1, is an essential component of the evolutionary-conserved polarity-regulating system, PAR-aPKC system, which plays indispensable roles in establishing asymmetric protein distributions and cell polarity in various biological contexts (Suzuki, A. and Ohno, S. (2006). J. Cell Sci., 119: 979-987; Matenia, D. and Mandelkow, E.M. (2009). Trends Biochem. Sci., 34: 332-342). PAR-1 is also known as MARK, which phosphorylates classical microtubule-associated proteins (MAPs) and detaches MAPs from microtubules (Matenia, D. and Mandelkow, E.M. (2009). Trends Biochem. Sci., 34: 332-342). This MARK activity of PAR-1 suggests its role in microtubule (MT) dynamics, but surprisingly, only few studies have been carried out to address this issue. Here, we summarize our recent study on live imaging analysis of MT dynamics in PAR-1b-depleted cells, which clearly demonstrated the positive role of PAR-1b in maintaining MT dynamics (Hayashi, K., Suzuki, A., Hirai, S., Kurihara, Y., Hoogenraad, C.C., and Ohno, S. (2011). J. Neurosci., 31: 12094-12103). Importantly, our results further revealed the novel physiological function of PAR-1b in maintaining dendritic spine morphology in mature neurons.
authors.affiliation: Department of Molecular Biology, Yokohama City University Graduate School of Medical Science, Yokohama, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Hayashi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suzuki
authors.forename: Shigeo
authors.initials: S
authors.lastname: Ohno
mesh_terms: D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D000818:Animals; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D008870:Microtubules / Q000201:enzymology / Q000378:metabolism*; D009474:Neurons / Q000201:enzymology*; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D008869:Microtubule-Associated Proteins; D017346:Protein Serine-Threonine Kinases