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Signaling-dependent phosphorylation of mitotic centromere-associated kinesin regulates microtubule depolymerization

Suresh B Pakala1, Vasudha S Nair, Sirigiri DivijendraNatha Reddy

  • 1Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, DC 20037, USA.

The Journal of Biological Chemistry
|October 12, 2012
PubMed
Abstract

Insights

p21-activated kinase 1 (PAK1) phosphorylates mitotic centromere-associated kinesin (MCAK), revealing a novel regulatory mechanism. This phosphorylation controls MCAK localization and microtubule depolymerization activity, impacting cellular functions.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • p21-activated kinase 1 (PAK1) is crucial for cytoskeleton and microtubule dynamics.
  • The specific role of PAK1 in regulating mitotic centromere-associated kinesin (MCAK) function was previously unknown.

Purpose of the Study:

  • To investigate the regulatory relationship between PAK1 and MCAK.
  • To elucidate the mechanistic insights into how PAK1 influences MCAK activity and localization.

Main Methods:

  • In vivo and in vitro phosphorylation assays.
  • Analysis of MCAK localization in mammalian cells.
  • Assessment of microtubule depolymerization activity.

Main Results:

  • PAK1 directly phosphorylates MCAK at serine 192 and serine 111.
  • PAK1 phosphorylation regulates MCAK's microtubule depolymerization activity.
  • PAK1 phosphorylation influences MCAK localization to centrosomes.

Conclusions:

  • Mitotic centromere-associated kinesin (MCAK) is a direct substrate of p21-activated kinase 1 (PAK1).
  • PAK1-mediated phosphorylation provides a novel mechanism for regulating MCAK function and localization.
  • This interaction is significant for understanding microtubule dynamics and mitotic processes.

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