Section: Rotations

Postdoctoral Position Available

Mitsuo Ikebe, Ph.D.

Academic Role: Professor

Faculty Appointment(s) In:
   Physiology

Other Affiliation(s):
   Biochemistry and Molecular Pharmacology
   Cell Dynamics Group
   Interdisciplinary Graduate Program

Rotation Projects

Project #1

Direct visualization of the movement of unconventional myosin motor drived actin filaments: Velocity, direction and processivity of the movement. Myosins are biological motor proteins which translocate actin filaments upon hydrolysis of ATP and plays a important role in diverse cellular motility. It has been evident recently that myosins constitute a superfamily of proteins which contain a conserved motor domain attached to diverse structurally distinct tail domains. Newly found myosins, called unconventional myosins, are different from conventional thick filament forming myosin and are supposed to play a fundamental role in various types of cell motility/contractility such as secretion, chemotaxis, endocytosis , phagocytosis, exocytosis, and vesicular trafficking,. However, most of the information available for the mammalian unconventional myosins is their cDNA structure, and the cell biological and biochemical/biophysical function of these motor proteins is still obscure. The project will directly determine the motor function of these "unconventional myosins" by monitoring the actin filament movement under fluorescent microscope.

In this project, a student would get experience in: 1) production of recombinant gene expression construct, 2) expression of the recombinant proteins by baculovirus expression system, 3) direct visualization of the movement of the fluorescent labeled actin filaments under fluorescent microscope.

Project #2

Translocation of protein kinases in living cells: direct visualization of the fluorescent labeled proteins in living cells and their movement by external stimuli. External stimuli by hormones and/or neurotransmitters initiates diverse transmembrane signaling that activates various cellular function characteristic to each cell type. In many events, cytosolic signaling molecules translocate their intracellular positions upon stimulation and this is thought to be critical to propagate the signal.

One group of such signal components are protein kinases/phosphatases. It is known that cell motility and contractility are regulated by phosphorylation of cytoskeleton and contractile apparatus in cells. Recent studies have suggested that two types of protein kinases influences one type of protein phosphatase activity that is specific to myosin thus regulating various cell motile and contractile processes such as cytokinesis, cell locamotion, and cytoskeletal rearrangement, and contraction. One is Rho kinase and/or protein kinase N that is downstream of small G-protein Rho family and the other is protein kinase C that is downstream of the membrane associated large G-proteins. Aim of this project is to determine the mechanism of G-protein signaling on cell contractility.

In this project students will be involved in the experiments of: 1) construction of green fluorescent protein (GFP) fusion constructs of these protein kinases; 2) gene transfection and expression of GFP fusion kinases in mammalian cells; 3) visualization of GFP tagged protein kinases in single living cells by digital fluorescent microscope and 3D image reconstitution.

Office: S4-308
Phone: 508-856-1954
Fax: 508-856-5997
E-mail: Mitsuo.Ikebe@umassmed.edu
Keywords: Intracellular Trafficking, Signal Transduction

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Postdoctoral Position Available A postdoctoral position is available to study in this laboratory. Contact Dr. Ikebe for additional details.