Isoform 3 of Plectin

Plectin isoform 3 (PLEC) is a large cytoplasmic protein that serves as a key scaffolding and cross-linking molecule in the cell (UniProt: Q15149-3). It plays a central role in organizing intermediate filaments and connecting them to other cellular structures, providing mechanical stability to cells and tissues. This function is particularly important in tissues subject to mechanical stress, such as muscle and skin.

Plectin is widely expressed across tissues and is essential for maintaining cellular architecture and integrity. Mutations in PLEC have been associated with muscular dystrophy and blistering disorders in the clinical literature, reflecting its critical structural role.

In Alzheimer's Disease, isoform 3 of plectin is significantly upregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics), with a mean log2 fold-change of 0.43 detected in human AD brain tissue using quantitative proteomics. This upregulation suggests plectin may be involved in cytoskeletal responses or compensatory mechanisms in the AD pathogenic process, though the functional consequence of this increase remains to be determined.