Cystatin-SN is a protein that in humans is encoded by the CST1gene.
The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions, where they appear to provide protective functions. The cystatin locus on chromosome 20 contains the majority of the type 2 cystatin genes and pseudogenes. This gene is located in the cystatin locus and encodes a cysteine proteinase inhibitor found in saliva, tears, urine, and seminal fluid.
Takahashi M, Honda Y, Ogawa K, Barka T (1993). "Immunofluorescence localization of cystatins in human lacrimal gland and in the exorbital lacrimal gland of the rat.". Acta ophthalmologica70 (5): 625–31. doi:10.1111/j.1755-3768.1992.tb02143.x. PMID1471486.
Isemura S, Saitoh E, Sanada K, Minakata K (1992). "Identification of full-sized forms of salivary (S-type) cystatins (cystatin SN, cystatin SA, cystatin S, and two phosphorylated forms of cystatin S) in human whole saliva and determination of phosphorylation sites of cystatin S.". J. Biochem.110 (4): 648–54. PMID1778989.
Al-Hashimi I, Dickinson DP, Levine MJ (1988). "Purification, molecular cloning, and sequencing of salivary cystatin SA-1.". J. Biol. Chem.263 (19): 9381–7. PMID2837486.
Saitoh E, Isemura S, Sanada K, et al. (1989). "Cystatin superfamily. Evidence that family II cystatin genes are evolutionarily related to family III cystatin genes.". Biol. Chem. Hoppe-Seyler. 369 Suppl: 191–7. PMID3202964.
Saitoh E, Kim HS, Smithies O, Maeda N (1988). "Human cysteine-proteinase inhibitors: nucleotide sequence analysis of three members of the cystatin gene family.". Gene61 (3): 329–38. doi:10.1016/0378-1119(87)90196-X. PMID3446578.
Isemura S, Saitoh E, Sanada K (1986). "Characterization of a new cysteine proteinase inhibitor of human saliva, cystatin SN, which is immunologically related to cystatin S.". FEBS Lett.198 (1): 145–9. doi:10.1016/0014-5793(86)81201-7. PMID3514272.
Dickinson DP, Thiesse M, Dempsey LD, Millar SJ (1993). "Genomic cloning, physical mapping, and expression of human type 2 cystatin genes.". Crit. Rev. Oral Biol. Med.4 (3–4): 573–80. PMID7690606.
Dickinson DP, Zhao Y, Thiesse M, Siciliano MJ (1995). "Direct mapping of seven genes encoding human type 2 cystatins to a single site located at 20p11.2". Genomics24 (1): 172–5. doi:10.1006/geno.1994.1595. PMID7896273.
Thiesse M, Millar SJ, Dickinson DP (1994). "The human type 2 cystatin gene family consists of eight to nine members, with at least seven genes clustered at a single locus on human chromosome 20". DNA Cell Biol.13 (2): 97–116. doi:10.1089/dna.1994.13.97. PMID8179826.
Henskens YM, van der Weijden FA, van den Keijbus PA, et al. (1996). "Effect of periodontal treatment on the protein composition of whole and parotid saliva". J. Periodontol.67 (3): 205–12. PMID8708950.
Deloukas P, Matthews LH, Ashurst J, et al. (2002). "The DNA sequence and comparative analysis of human chromosome 20". Nature414 (6866): 865–71. doi:10.1038/414865a. PMID11780052.
Dickinson DP, Thiesse M, Hicks MJ (2002). "Expression of type 2 cystatin genes CST1-CST5 in adult human tissues and the developing submandibular gland". DNA Cell Biol.21 (1): 47–65. doi:10.1089/10445490252810311. PMID11879580.