Protein SCAI

Protein SCAI (Q8N9R8) is a 606-amino-acid tumor suppressor that regulates cell migration and transcriptional activity. It functions to suppress MRTFA-induced SRF transcriptional activity and may participate in the RHOA-DIAPH1 signal transduction pathway, with roles in regulating integrin β1 (ITGB1) expression (UniProt: Q8N9R8).

SCAI operates primarily in cellular signaling pathways controlling actin dynamics and migration. UniProt lists no specific disease associations for this protein in their curated annotations.

In Alzheimer's Disease, SCAI shows consistent downregulation in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of −2.43 across subcellular fractions (Chaparral AD proteomics). This reduction was detected via TMT-labeled quantitative proteomics across multiple cellular compartments (P2, P3, S2, S3 fractions), suggesting a possible loss of SCAI-mediated transcriptional suppression in the AD brain microenvironment.