Health / Medical Topics |
Stathmin Pathway
Stathmin is a ubiquitous, cytosolic 19-kDa protein, that is phosphorylated on up to four sites in response to many regulatory signals within cells. Its molecular characterization indicates a functional organization including an N-terminal regulatory domain that bears the phosphorylation sites linked to a putative alpha-helical binding domain predicted to participate in coiled-coil, protein-protein interactions. In addition to the protein kinases that phosphorylate Stathmin such as CaMK, MAPK, p34cdc2, PKA, a few other proteins have been suggested to interact with stathmin in vivo. One of them was identified as BiP, a member of the hsp70 heat-shock protein family. Another is a previously unidentified, putative serine/threonine kinase, KIS, which might be regulated by stathmin or, more likely, be part of the kinases controlling its phosphorylation state. Finally, proteins CC1 and CC2, predicted to form alpha-helices participating in coiled-coil interacting structures. It has been suggest that the action of antimicrotubule drugs can be affected by stathmin in at least two ways: (a) altered drug binding; and (b) growth arrest at the G2 to M boundary. Mutant p53 breast cancers exhibiting high levels of stathmin may be resistant to antimicrotubule agents. (NCI Thesaurus/BIOCARTA)