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Laboratory of Cell Signaling and Development (CSD Lab)

Department of Molecular Biosceinces, Faculty of Life Sciences

Kyoto Sangyo University

 
 

CSD Lab: Introduction to Myself


Ken-ichi Sato was born in Hokkaido, Japan. He graduated from Faculty of Science, Kobe University, Kobe, Japan, in 1988. He obtained his Ph.D. degree in biology from the Graduate School of Science and Technology, Kobe University, in 1996. From 1991 to 2007, he worked as an Assistant Professor in the Laboratory of Dr. Yasuo Fukami at the Research Center for Environmental Genomics, Kobe University, where he investigated the regulatory mechanism and physiological functions of the protein tyrosine kinase Src in frog egg fertilization and in human cancer cells. In 2002, as a visiting scholar in the Laboratory of Dr. Rafael A. Fissore at the University of Massachusetts at Amherst, MA, USA, he learned and studied mammalian fertilization. In 2007, he launched his own research group of Cell Signaling and Development in Kyoto Sangyo University, Kyoto, Japan. Throughout almost all of carrier, he has been interested in the roles played by protein-tyrosine kinases in transmembrane signal transduction mechanisms such as in the cancer cells and in the fertilized eggs. Currently, he is a Professor at the Department of Molecular Biosciences, Faculty of Life Sciences, Kyoto Sangyo University.


CSD Lab: Introduction to Our Research

Biological Functions of Eggs and Cancer Cells:

Transmembrane signal transduction and beyond


Membrane microdomains (MDs) or lipid/membrane rafts are distinct areas on the plasma membranes, where a specific subset of lipids (e.g. cholesterol, sphingolipids) and proteins (e.g. glycosylphosphatidylinositol-anchored proteins, growth factor receptor/kinases) are assembling and functioning for several aspects of cellular functions.  Our recent investigation has revealed that fertilization of African clawed frog, Xenopus laevis, requires cholesterol-dependent architectures of the egg MDs, where the Src tyrosine kinase, which is required for sperm-induced developmental activation of egg (in short, egg activation), is concentrated.  Moreover, fertilization of Xenopus eggs involves proteolytic cleavage of the extracellular part and subsequent phosphorylation of a cytoplasmic tyrosine residue of uroplakin III (UPIII), an egg MD-associated protein.  Protease activity toward UPIII seems to be derived from fertilizing sperm, while phosphorylation of UPIII seems to be catalyzed by Src.  Therefore, it is assumed that UPIII serves an integral part of signal transduction in fertilization of Xenopus.  Our more recent study on human cancer cells has revealed that a similar but distinct arrays of signal transduction operates in anti-apoptotic growth of cells.  Namely, in human bladder carcinoma cells, cooperation of UPIII and Src, both of which localize to the MDs, allows cells to escape from apoptotic cell death and proliferate under culture conditions deprived of serum.  Thus, research in our laboratory is dealing with the molecular and cellular basis of the fertilization mechanisms of frog egg (the Egg Project) and the anti-apoptosis mechanisms of human cancer cells (the Cancer Cell Project).


Research Background and problems on Egg Project and Cancer Cell Project


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