SERPINA1
The protein encoded by this gene is secreted and is a serine protease inhibitor whose targets include elastase, plasmin, thrombin, trypsin, chymotrypsin, and plasminogen activator. Defects in this gene can cause emphysema or liver disease. Several transcript variants encoding the same protein have been found for this gene. [provided by RefSeq, Jul 2008]
Full Name
Serpin Family A Member 1
Function
Inhibitor of serine proteases. Its primary target is elastase, but it also has a moderate affinity for plasmin and thrombin. Irreversibly inhibits trypsin, chymotrypsin and plasminogen activator. The aberrant form inhibits insulin-induced NO synthesis in platelets, decreases coagulation time and has proteolytic activity against insulin and plasmin.
Short peptide from AAT
Reversible chymotrypsin inhibitor. It also inhibits elastase, but not trypsin. Its major physiological function is the protection of the lower respiratory tract against proteolytic destruction by human leukocyte elastase (HLE).
Biological Process
Biological Process acute-phase responseIEA:UniProtKB-KW
Biological Process blood coagulationIEA:UniProtKB-KW
Biological Process negative regulation of endopeptidase activityManual Assertion Based On ExperimentIBA:GO_Central
Cellular Location
Secreted
Endoplasmic reticulum
The S and Z allele are not secreted effectively and accumulate intracellularly in the endoplasmic reticulum.
Short peptide from AAT
Secreted, extracellular space, extracellular matrix
Involvement in disease
Alpha-1-antitrypsin deficiency (A1ATD):
A disorder whose most common manifestation is emphysema, which becomes evident by the third to fourth decade. A less common manifestation of the deficiency is liver disease, which occurs in children and adults, and may result in cirrhosis and liver failure. Environmental factors, particularly cigarette smoking, greatly increase the risk of emphysema at an earlier age.
PTM
N-glycosylated. Differential glycosylation produces a number of isoforms. N-linked glycan at Asn-107 is alternatively di-antennary, tri-antennary or tetra-antennary. The glycan at Asn-70 is di-antennary with trace amounts of tri-antennary. Glycan at Asn-271 is exclusively di-antennary. Structure of glycans at Asn-70 and Asn-271 is Hex5HexNAc4. The structure of the antennae is Neu5Ac(alpha1-6)Gal(beta1-4)GlcNAc attached to the core structure Man(alpha1-6)[Man(alpha1-3)]Man(beta1-4)GlcNAc(beta1-4)GlcNAc. Some antennae are fucosylated, which forms a Lewis-X determinant.
Proteolytic processing may yield the truncated form that ranges from Asp-30 to Lys-418.
(Microbial infection) Proteolytically processed by Staphylococcus aureus seryl, cysteinyl, and metallo-proteases.