Katsuhide Mabuchi, Ph.D.
Senior Research Associate
Email: kmabuchi at bbri.org

Research Summary
Phosphorylation of proteins are involved in the regulation of enzyme activity, enzyme substrate specificity and formation of functional multi-unit complexes. One enzyme, PP1c delta protein phosphatase removes a phosphate from many different phospho-proteins. Very uniquely, the enzyme can form complexes with different regulatory subunits to become more or less specific to one phosphoprotein. In the case of myosin light chain phosphatase, the delta catalytic enzyme is complexed with myosin targeting and the second small proteins forming a trimeric holoenzyme. We are studying how the non-catalytic subunits alter activity and substrate specificity under the directorship by Dr. T. Tao. In addition, I use an electron microscopic method to visualize individual protein molecules. The method is particularly suited to examine variation among different molecules.

Selected Publications
Li, X. D., Mabuchi, K., Ikebe, R., Ikebe, M. Ca2+-induced activation of ATPase activity of myosin Va is accompanied with a large conformational change. Biochem Biophys Res Commun, 315, 538-545, 2004 [abstract in PubMed]

Takizawa N, Schmidt DJ, Mabuchi K, Villa-Moruzzi E, Tuft RA, Ikebe M. M20, the small subunit of PP1M, binds to microtubules. Am J Physiol Cell Physiol. 2003 Feb;284(2):C250-62. [abstract in PubMed]

Mabuchi K, Li Y, Carlos A, Wang CL, Graceffa P. Caldesmon exhibits a clustered distribution along individual chicken gizzard native thin filaments. J Muscle Res Cell Motil 2001;22(1):77-90 [abstract in PubMed]

Langsetmo K, Stafford WF 3rd, Mabuchi K, Tao T. Recombinant small subunit of smooth muscle myosin light chain phosphatase. Molecular properties and interactions with the targeting subunit. J Biol Chem. 2001 Sep 7;276(36):34318-22. [abstract in PubMed]

Mabuchi K, Gong BJ, Langsetmo K, Ito M, Nakano T, Tao T Isoforms of the small non-catalytic subunit of smooth muscle myosin light chain phosphatase. Biochim Biophys Acta 1999 Oct 12;1434(2):296-303 [abstract in PubMed]

PubMed:
Click here for a list of publications (searches the National Library of Medicine's PubMed database.)