Adaptor related protein complex 4 subunit beta 1 (AP4B1) (AP4B1)

Adaptor related protein complex 4 subunit beta 1 (AP4B1) is a critical component of the heterotetrameric AP-4 complex, which functions as a vesicle coat at the trans-Golgi network (TGN) [1, 15]. It plays a vital role in the selective sorting and transport of transmembrane cargo proteins, most notably the autophagy protein ATG9A, from the TGN to the endosomal-lysosomal system [4, 21]. In the central nervous system, AP4B1 is essential for the proper asymmetric localization of proteins within the somatodendritic compartment of neurons [1, 2]. Mutations in the AP4B1 gene lead to AP-4 deficiency, causing Spastic Paraplegia 47 (SPG47), a severe neurodegenerative disorder characterized by progressive spasticity, intellectual disability, and epilepsy [1, 15, 16]. While no drugs are currently approved, AP4B1 is a primary target for gene replacement therapies, such as AAV9/hAP4B1, which aim to restore functional protein levels and correct cellular trafficking defects [4, 6, 8]. Small molecule candidates like rutin are also being investigated for their potential to stabilize subunit interactions and rescue complex function [9].

Other names

AP4B1BETA-4SPG47Adaptor Related Protein Complex 4 Beta 1 SubunitAP-4 Adaptor Complex Subunit BetaBeta 4 Subunit Of AP-4Beta4-AdaptinAdaptor-Related Protein Complex 4 Subunit Beta-1Beta Subunit Of AP-4CPSQ5

Gene replacement therapy to restore functional protein levels; Small molecule stabilization of protein-protein interactions (chaperone-like effect) [4, 6, 9].