Protein tyrosine phosphatase type IVA 1

PTP4A1 (protein tyrosine phosphatase type IVA 1) is a small serine/threonine phosphatase that regulates cell-cycle progression by stimulating the G1/S phase transition during mitosis (UniProt: Q93096). It also promotes epithelial tissue development and maintenance, and has been implicated in enhancing cell proliferation, motility, and invasive activity in cancer contexts.

PTP4A1 expression is broadly distributed across tissues, though UniProt records no specific disease associations in its curated function field. The protein's role in cell-cycle regulation and proliferation suggests potential relevance to tissue homeostasis across multiple organ systems.

In Alzheimer's disease, PTP4A1 is upregulated in post-mortem AD brain tissue compared to age-matched controls (mean log2 fold-change: +0.5743), as detected by quantitative proteomics in subcellular fractions (Chaparral AD proteomics). This elevation suggests altered cell-cycle or proliferative signaling in AD pathology, though the specific contribution to AD pathogenesis remains to be determined.