Signal-induced proliferation-associated protein 1 (SIPA1)

Signal-induced proliferation-associated protein 1 (SIPA1) is a protein encoded by the SIPA1 gene, known for its GTPase-activating activity towards the Rap1 and Rap2 subfamily of small GTPases[4][5]. In addition to its canonical role as an enzyme, SIPA1 has been newly characterized as a transcription factor that binds DNA directly and regulates key genes involved in cell adhesion, migration, and cancer progression, including integrin β1 and ABCB1[1][2]. SIPA1 is highly expressed in lymphohematopoietic tissues and functions both in the cytoplasm and nucleus[2]. Its expression and genetic variants have been linked to increased metastatic potential and poor prognosis in several human cancers, indicating its relevance as a therapeutic target and prognostic biomarker[2][3][1]. SIPA1 interacts with proteins like importin β1, AF6/afadin, AQP2, and Brd4, influencing processes such as cell junction stability and cell cycle control[2][3]. Research is ongoing to clarify its full clinical targeting potential.

Other names

SIPA1SPA1Sipa-1GTPase-activating protein Spa-1p130 SPA-1signal-induced proliferation-associated gene 1

Rap1 GTPase pathway inhibition; Sequence-specific transcriptional regulation (activates promoter activity for key cancer-related genes, e.g. integrin β1, ABCB1)