Protein EFR3 homolog B (EFR3B)

Protein EFR3 homolog B (EFR3B) is a peripheral membrane protein found in humans that plays a crucial role in anchoring the phosphatidylinositol 4-kinase alpha (PI4KA) complex to the plasma membrane[1][3]. This anchoring is essential for the synthesis and regulation of phosphatidylinositol 4-phosphate (PtdIns4P), a lipid critical for membrane identity, signaling, and trafficking[1][2][3]. EFR3B belongs to the armadillo (ARM)-repeat superfamily of proteins, forming superhelical rod-like structures that facilitate protein-protein interactions[1]. Its N-terminal region is palmitoylated, which determines plasma membrane localization and modulates its association with both membrane rafts and TMEM150A[1][2]. EFR3B is one of two paralogs in mammals, the other being EFR3A; both share core functions but may differ in regulatory details—particularly phosphorylation and potential tissue distribution[1][2]. Disruption of EFR3B or its associated complex partners can affect GPCR signaling, phosphoinositide signaling, and has been associated with disease settings such as cancer, neurological, and cardiovascular disorders, albeit its direct role as a therapeutic target is not established[1][2][3]. EFR3B’s principal known molecular function is the stable recruitment and localization of the PI4KA complex alongside TTC7(FAM126) proteins at the plasma membrane, a process critical for maintaining phosphoinositide homeostasis[1][2][3]. Key points: - EFR3B is not itself a receptor, enzyme, or traditional drug target, but a scaffold protein critical for membrane localization of kinase complexes and thus proper signal transduction[1][2][3]. - Mutations or dysfunctions in EFR3B or its complex may contribute to disease phenotypes, mostly indirectly via disruption of cellular signaling[1][2]. - No drugs are currently known to directly interact with EFR3B, nor is there evidence of EFR3B acting as a biomarker or being associated with specific safety/therapeutic concerns[3].

Other names

EFR3BKIAA0953FLJ37871protein EFR3 homolog B