Serum amyloid A-like protein 1 (SAAL1)

Serum amyloid A-like protein 1 (SAAL1) is a 474-amino acid acidic protein (approximate mass 54 kDa) encoded by the SAAL1 gene on chromosome 11p15.1. SAAL1 belongs to the serum amyloid A superfamily but is a distinct gene and protein from classic acute-phase serum amyloid A isoforms. SAAL1 is ubiquitously expressed at moderate levels, with highest levels in testis, and is present in both nuclear and cytoplasmic compartments depending on cell type. It is functionally important in promoting the proliferation and cell cycle progression of synovial fibroblasts under inflammatory conditions, and its overexpression is associated with pathogenesis in rheumatoid arthritis and osteoarthritis, as well as in the progression and poor prognosis of several human cancers, including hepatocellular carcinoma. Mechanistically, SAAL1 mediates G1/S transition by stabilizing CDK6 mRNA and is implicated in inflammation-associated cell cycle regulation and tumorigenesis. Pan-cancer analyses suggest that high SAAL1 expression may predict an immune-inflamed tumor phenotype and potentially enhanced response to immunotherapies. SAAL1 also interacts with several viral proteins and immunity-regulating proteins, suggesting broader roles in host defense and innate immunity.

Other names

SAAL1SPACIA1Synoviocyte proliferation-associated in collagen-induced arthritis protein 1Synoviocyte proliferation-associated in collagen-induced arthritis 1serum amyloid A like 1

No direct targeting drugs described. Modulation of SAAL1 (e.g., by siRNA knockdown) affects cell proliferation and migration, increases sensitivity to kinase inhibitors like sorafenib and foretinib in cancer models