VPS33A

Description

The VPS33A (VPS33A core subunit of CORVET and HOPS complexes) is a protein-coding gene located on chromosome 12.

VPS33A is a protein encoded by the VPS33A gene in humans. It is a member of the Sec-1 domain family, similar to the yeast class C Vps33 protein. VPS33A is primarily associated with late endosomes and lysosomes and is believed to play a critical role in the movement of vesicles within the cell, particularly in the endosome/lysosome pathway. Mutations in VPS33A have been linked to a syndrome known as Mucopolysaccharidosis-plus syndrome.

VPS33A plays a crucial role in the fusion of endosomes and autophagosomes with lysosomes, a process essential for the proper degradation of cellular waste and the recycling of cellular components. This function is dependent on its association with VPS16 but not VIPAS39. VPS33A's involvement in autophagosome-lysosome fusion specifically implicates STX17 but not UVRAG. VPS33A is a core component of two key endosomal tethering complexes: HOPS and CORVET. The HOPS complex is believed to be recruited to Rab7 on the late endosomal membrane and to regulate late endocytic, phagocytic, and autophagic traffic towards lysosomes. The CORVET complex is proposed to function as a Rab5 effector to mediate early endosome fusion, likely in specific endosome subpopulations.

VPS33A is also known as MPSPS.

Associated Diseases

• Mucopolysaccharidosis-like syndrome with congenital heart defects and hematopoietic disorders
• Mucopolysaccharidosis-Plus syndrome