Small proline-rich protein 1A (SPRR1A)

Small proline-rich protein 1A is a structural protein primarily involved in the formation of the cornified envelope in terminally differentiating keratinocytes, contributing to skin barrier function. It is a member of the small proline-rich protein family and is encoded in the epidermal differentiation complex on chromosome 1q21. SPRR1A acts as a precursor that is ultimately cross-linked by transglutaminase to form an insoluble layer beneath the plasma membrane. Originally a squamous cell differentiation marker, SPRR1A can be stress-inducible in non-squamous tissues such as heart and neuronal cells, where it supports cytoprotection, tissue remodeling, and regeneration after injury. SPRR1A is upregulated in various cancers and tissue injuries, and its high expression is often associated with poor prognosis, particularly in pancreatic ductal adenocarcinoma and other malignancies

Other names

Cornifin-ASPRKSPR-IA19 kDa pancornulinSmall proline-rich protein IAPancornulin

Not applicable, as no drugs directly target SPRR1A. Its induction results from cellular signaling pathways (e.g., the gp130 pathway) and it exerts cytoprotective and structural roles