ID:IC1_HUMAN DESCRIPTION: RecName: Full=Plasma protease C1 inhibitor; Short=C1 Inh; Short=C1Inh; AltName: Full=C1 esterase inhibitor; AltName: Full=C1-inhibiting factor; AltName: Full=Serpin G1; Flags: Precursor; FUNCTION: Activation of the C1 complex is under control of the C1- inhibitor. It forms a proteolytically inactive stoichiometric complex with the C1r or C1s proteases. May play a potentially crucial role in regulating important physiological pathways including complement activation, blood coagulation, fibrinolysis and the generation of kinins. Very efficient inhibitor of FXIIa. Inhibits chymotrypsin and kallikrein. SUBUNIT: Binds to E.coli stcE which allows localization of SERPING1 to cell membranes thus protecting the bacteria against complement-mediated lysis. Interacts with MASP1. SUBCELLULAR LOCATION: Secreted. PTM: Highly glycosylated (49%) with N- and O-glycosylation. O- glycosylated with core 1 or possibly core 8 glycans. N-glycan heterogeneity at Asn-25: Hex5HexNAc4 (minor), dHex1Hex5HexNAc4 (minor), Hex6HexNAc5 (major) and dHex1Hex6HexNAc5 (minor). PTM: Can be proteolytically cleaved by E.coli stcE. POLYMORPHISM: Chymotrypsin uses Ala-465 as its reactive site in normal plasma protease C1 inhibitor, and His-466 as its reactive site in the variant His-466. DISEASE: Defects in SERPING1 are the cause of hereditary angioedema (HAE) [MIM:106100]; also called hereditary angioneurotic edema (HANE). HAE is an autosomal dominant disorder characterized by episodic local subcutaneous edema and submucosal edema involving the upper respiratory and gastrointestinal tracts. HAE due to C1 esterase inhibitor deficiency is comprised of two clinically indistinguishable forms. In HAE type 1, representing 85% of patients, serum levels of C1 esterase inhibitor are less than 35% of normal. In HAE type 2, the levels are normal or elevated, but the protein is non-functional. SIMILARITY: Belongs to the serpin family. SEQUENCE CAUTION: Sequence=AAA53096.1; Type=Erroneous gene model prediction; WEB RESOURCE: Name=Wikipedia; Note=C1-inhibitor entry; URL="http://en.wikipedia.org/wiki/C1-inhibitor"; WEB RESOURCE: Name=SERPING1base; Note=SERPING1 mutation db; URL="http://bioinf.uta.fi/SERPING1base/"; WEB RESOURCE: Name=GeneReviews; URL="http://www.ncbi.nlm.nih.gov/sites/GeneTests/lab/gene/SERPING1"; WEB RESOURCE: Name=SeattleSNPs; URL="http://pga.gs.washington.edu/data/serping1/";
The RNAfold program from the Vienna RNA Package is used to perform the secondary structure predictions and folding calculations. The estimated folding energy is in kcal/mol. The more negative the energy, the more secondary structure the RNA is likely to have.
ModBase Predicted Comparative 3D Structure on P05155
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Orthologous Genes in Other Species
Orthologies between human, mouse, and rat are computed by taking the best BLASTP hit, and filtering out non-syntenic hits. For more distant species reciprocal-best BLASTP hits are used. Note that the absence of an ortholog in the table below may reflect incomplete annotations in the other species rather than a true absence of the orthologous gene.
US Server
Sequence and Links to Tools and Databases 
Common Gene Haplotype Alleles 
