Research Structural basis of protein phosphorylation control. The general interest of my laboratory is to understand how extracellular signals are integrated intracellularly to produce biological responses. Such signal transduction pathways control many important cellular processes such as cell division, differentiation and immune response. Defects of these tightly regulated and highly cooperative signal transduction pathways lead to abnormal cell growth and immune response. These studies are of fundamental importance in understanding how signal transduction is controlled.
T cells play critical roles in host immune responses to pathogens.
CD45 is composed of an extracellular receptor-like domain and an intracellular portion containing two tandemly arranged PTPase domains. The tandem PTPase structure is found in almost all other transmembrane PTPases, yet little is known about the function of this arrangement. In CD45, only the membrane proximal domain has catalytic function, whereas the role of the membrane distal domain has been controversial. We are interested in understanding the structural basis by which CD45 and lck interact to achieve TCR signal regulation. Several smad proteins have been characterized in vertebrates.