The Expression And Its Mechanism Of Mammalian Sterile 20-like Kinase 3 (mst3) In The Development Of Mouse Embryo

Eukaryotic cells are able to couple extracellular signals to specific biological processes such as cell growth, differentiation, and stress response though the activation of distinct evolutionarily conserved intracellular signaling cascades, collectively known as mitogen-activated protein kinase(MAPK) cascades. In both mammals and lower eukaryotes, the core of MAP kinase cascades is a thee-compontent module consisting of a generic MAPK kinase kinase, which phosphorylates and activates a dual-specificity MAPK kinase, which in turn activates the MAPK. In many cases the activated MAP kinases translocate to the nucleus where they phosphorylate transcription factors, thus eliciting the biological response.Based on epistasis experiments, the S.cerevisiae serine-theonine kinase STE20 was placed upstream of the MAPK module consisting of the MAPK kinase kinase STE11, the MAPK kinase STE7, and the MAPKs FUS3/KSS1 in the mating pathway.The mammalian STE20-related kinases represent a rapidly growing kinase family. Based on their structure and regulation, members of the STE20 family can be divided into two subfamilies. First, like STE20 and Cla-4, the mammalian PAKs consist of a C-terminal kinase domain and an N-terminal regulatory domain and have a small GTPase Racl/Cdc42 binding region. PAKs bind to GTP-Cdc42 and Rac but not Rho. Upon binding they autophosphorylate and are activated. Second, all other STE20-like kinase identified thus far resemble SPS1 in that they possess an N-terminal kinase domain and a C-terminal regulatory domain and do not contain a small GTPase Rac-1/Cdc42-binding domain.Mammalian sterile 20 like kinase 3(mst3) was recently found as a member of...