• PMID: 10520577
• Gene Name: MET
• Condition: Role in sperm function
• Association: Associated
• Sex: Male
• Infertility type: Male infertility
• Other associated phenotypes: Role in sperm function

Presence and tyrosine phosphorylation of c-met receptor in human sperm

Herness EA, Naz RK.

The c-met receptor is a p190MET tyrosine kinase proto-oncoprotein that through its binding to its ligand, designated hepatocyte growth factor (HGF), induces mitogenic, motogenic, and morphogenic activities in a variety of cell types. The present study was conducted to examine whether or not the c-met receptor is expressed and tyrosine phosphorylated in the human sperm cell. The Western blot analysis, using a monoclonal antibody (MAb2) directed against the extracellular domain of the c-met receptor, showed a specific band of 195 kDa corresponding to the intact c-met receptor in the detergent-solubilized human sperm preparation (HSP). This protein band was not recognized by the control myeloma lg (immunoglobin). In the immunoprecipitation procedure, a similar specific band of 195 kDa and a 145-kDa band corresponding to the beta-subunit of c-met receptor were seen. In the indirect immunofluorescence technique, the c-met receptor was localized predominantly in the acrosomal region of the sperm cell. The c-met receptor was tyrosine phosphorylated/autophosphorylated during capacitation and in the cell-free in vitro kinase assay. Incubation of human sperm with hepatocyte growth factor (HGF) or MAb2 to c-met receptor enhanced the degree of tyrosine phosphorylation/autophosphorylation of the c-met receptor up to 5.1-fold. These findings indicate that the c-met receptor is present in the acrosomal region of human sperm cell and is tyrosine phosphorylated, which is enhanced by HGF and the receptor antibody. The c-met system may have an important role in sperm function. FAU - Herness, E A AU - Herness EA AD - Department of Obstetrics and Gynecology, Medical College of Ohio, Toledo 43614-5806, USA.