Isoform 6 of Tropomyosin alpha-1 chain

Tropomyosin alpha-1 chain (TPM1) is a cytoskeletal protein that functions as a regulatory component of the actin filament system, controlling muscle contraction and cell motility (UniProt: P09493-6). This isoform (isoform 6, 284 amino acids) is one of several products generated from the TPM1 locus through alternative splicing. Tropomyosins are widely expressed across tissues and play fundamental roles in actin dynamics and cellular architecture.

TPM1 is curated in Chaparral as relevant to Alzheimer's Disease pathology. In post-mortem AD brain tissue compared to age-matched controls, this isoform showed increased abundance with a mean log2 fold-change of +1.48 (Chaparral AD proteomics), indicating up-regulation in AD. The proteomics experiment employed TMT labeling and data-dependent acquisition (DDA) across four subcellular fractions (P2, P3, S2, S3), though the measurement was detected in a single fraction. The up-regulation of TPM1 may reflect cytoskeletal remodeling or compensatory responses to neurodegeneration observed in AD brain tissue.