Serpina3g

Developmental stage

T-cell specific expression rises during the differentiation of CD8 T-cell progenitors into memory CD8 T-cells.

Domain

The reactive center loop (RCL) extends out from the body of the protein and directs binding to the target protease. The protease cleaves the serpin at the reactive site within the RCL, establishing a covalent linkage between the serpin reactive site and the protease. The resulting inactive serpin-protease complex is highly stable (By similarity). Variability within the reactive center loop (RCL) sequences of Serpina3 paralogs may determine target protease specificity.

Function

Serine and cysteine protease inhibitor. Can inhibit lysosomal papain-like proteases including the cathepsins B, G, H, K, L and V. Ineffective against elastase, granzyme A, granzyme B, or caspases 3, 8 or 9. Inhibition of cytoplasmic cathepsin B following release from the lysosome may protect cells from apoptosis. This may facilitate the survival of progenitor T-cells and the subsequent development of long term memory CD8 T-cells.

Sequence Similarities

Belongs to the serpin family.

Tissue Specificity

Expressed in bone marrow (particularly hematopoietic stem cells), heart, kidney, liver, lung, skeletal muscle, spleen, testis, thymus and T-cells.

Cellular localization

• Cytoplasm
• Nucleus

Alternative names

Spi2A, Serpina3g, Serine protease inhibitor A3G, Serpin A3G, Serine protease inhibitor 2A, Serpin 2A

Database links

swissprot:Q5I2A0 swissprot:Q3U0Y1 swissprot:Q4V9W0 entrezGene:20715