Compositions and methods comprising cytostatic protein kinase

摘要

The present invention presents a unique class of physiological suppressors of cell division and cleavage. In particular, the present invention presents p21-activated protein kinase PAK I, also known as protease activated protein kinase I (with the same abbreviation "PAK I") which has been purified to apparent homogeneity. PAK I is inactive, e.g. as a protein of about 60 kDa (denoted "p60", as determined by polyacrylamide gel electrophoresis) and is active when autophosphorylated, for example, following limited proteolysis, or binding of Cdc42, e.g., as a protein of about 58 kDa (denoted "p58" as determined by polyacrylamide gel electrophoresis). The present invention also presents a fragment of PAK I, a peptide denoted p37, which contains the catalytic domain of PAK I. The purification, characterization, nucleotide and amino acid sequences of PAK I and p37 are also disclosed. Another aspect of the invention discloses the cytostatic activity of PAK I and its fragments. Further disclosed are the uses of these proteins and peptides for diagnosing and treating diseases, especially for cancer.