Phosphatidylinositol transfer protein beta (PITPNB)

Phosphatidylinositol transfer protein beta (PITPNB) is a monomeric, cytosolic protein primarily responsible for shuttling phosphatidylinositol, phosphatidylcholine, and sphingomyelin between membrane compartments, facilitating their availability for signaling and biosynthetic processes[1][2][3][4][6]. PITPNB is essential for the biosynthesis of polyphosphoinositides and thus crucial for cell signaling pathways—including those involved in platelet activation and tumor metastasis—by acting both as a lipid transporter and as a cofactor that presents lipids to specific kinases[2]. It plays a nonredundant role alongside its paralog PITPNA (alpha isoform), and while both isoforms can compensate partially for one another, each has unique contributions to membrane dynamics and cellular function[2]. PITPNB is expressed ubiquitously in human tissues and is linked to several disease states, with research ongoing to clarify its broader therapeutic significance[1][5][6].

Other names

Phosphatidylinositol transfer protein beta isoformPITPNBPI-TP-betaPtdIns transfer protein betaPtdInsTP betaVIB1BPtdInsTPphosphatidylinositol transfer protein beta isoformphosphotidylinositol transfer proteinbeta