serpin B5; protease inhibitor 5; maspin (SERPINB5, PI5)

Function

• tumor suppressor
• blocks growth, invasion, & metastatic properties of mammary tumors
• possibly reduces invasion through basement membrane
• as it does not undergo the S (stressed) to R (relaxed) conformational transition characteristic of active serpins, it exhibits no serine protease inhibitory activity

Structure

belongs to the serpin family, Ov-serpin subfamily

Compartment

secreted, extracellular space

Alternative splicing

named isoforms=2

Expression

• expressed in normal mammary epithelial cells, but not in most mammary carcinoma cell lines

More general terms

• serine protease inhibitor; serpin
• anti-oncoprotein (tumor suppressor protein)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=5268
• OMIM: https://mirror.omim.org/entry/154790
• UniProt: http://www.uniprot.org/uniprot/P36952.html