Isoform 5 of Sorbin and SH3 domain-containing protein 1

Sorbin and SH3 domain-containing protein 1 (SORBS1) is a cytoplasmic adaptor protein containing sorbin homology and multiple SH3 domains, which mediate protein-protein interactions in cellular signaling (UniProt: Q9BX66). The protein is involved in actin cytoskeleton organization and signal transduction pathways, with expression across multiple tissues. SORBS1 isoform 5 is a 1004 amino acid variant of this multi-domain scaffold protein.

In the context of Alzheimer's Disease, SORBS1 isoform 5 is upregulated in post-mortem AD brain tissue relative to age-matched controls. Analysis of human AD brain samples using subcellular fractionation (P2, P3, S2, S3) and tandem mass tag (TMT) proteomics detected a mean log2 fold-change of +0.43 (Chaparral AD proteomics). The modest but consistent upregulation suggests potential involvement in AD-associated pathophysiological processes, though the specific mechanistic contribution remains to be elucidated. Further investigation of SORBS1's role in cytoskeletal dynamics and synaptic function may clarify its relevance to neurodegeneration.