Stefins
Synonyms
Definition
Stefins are members of the cystatin superfamily of cysteine proteinase inhibitors localized in the cytosol and thought to protect cytoskeletal proteins from degradation by cysteine proteases released from lysosomes.
Characteristics
Type I or family 1 of the cystatin superfamily of cysteine protease inhibitors includes human stefins A and B and their homologues in other species such as cystatinsα and β in rat, bovine thymus stefin C, porcine thymus stefins D1 and D2, mouse stefin A (1–4), and others (see MEROPS subfamily I25A). The genes for human stefins A and B have been mapped to chromosomes 3q21 and 21q22.3, respectively. The lack of a signal sequence and disulfide bonds makes stefins distinct from other members of the cystatin superfamily. Stefins are single-chain proteins consisting of 98–103 amino acid residues, with a molecular mass of 11–12 kDa. Human stefin A is an acidic protein with pI values between 4.5 and 5.0, whereas...
Keywords
Cysteine Protease Cysteine Protease Inhibitor Cysteine Protease Activity Cysteine Cathepsin Psoriatic EpidermisReferences
- Keppler D (2006) Towards novel anti-cancer strategies based on cystatin function. Cancer Lett 235:159–176CrossRefPubMedGoogle Scholar
- Kos J, Lah T (2006) Role of cystatins and stefins in cancer. In: Zerovnik E, Kopitar-Jerala N, Uversky V (eds) Human stefins and cystatins. Nova Science Publisher, New York, pp 153–165Google Scholar
- Kos J, Krasovec M, Cimerman N et al (2000) Cysteine proteinase inhibitors stefin A, stefin B and cystatin C in sera from patients with colorectal cancer: relation to prognosis. Clin Cancer Res 6:505–511PubMedGoogle Scholar
- Strojan P, Budihna M, Smid L et al (2000) Prognostic significance of cysteine proteinases cathepsins B and L and their endogenous inhibitors stefins A and B in patients with squamous cell carcinoma of the head and neck. Clin Cancer Res 6:1052–1062PubMedGoogle Scholar
- Turk V, Kos J, Turk B (2004) Cysteine cathepsins (proteases) – on the main stage of cancer? Cancer Cell 5:409–410CrossRefPubMedGoogle Scholar