HPS1

This gene encodes a protein that may play a role in organelle biogenesis associated with melanosomes, platelet dense granules, and lysosomes. The encoded protein is a component of three different protein complexes termed biogenesis of lysosome-related organelles complex (BLOC)-3, BLOC4, and BLOC5. Mutations in this gene are associated with Hermansky-Pudlak syndrome type 1. Alternative splicing results in multiple transcript variants. A pseudogene related to this gene is located on chromosome 22. [provided by RefSeq, Aug 2015]

Full Name

HPS1, Biogenesis Of Lysosomal Organelles Complex 3 Subunit 1

Function

Component of the BLOC-3 complex, a complex that acts as a guanine exchange factor (GEF) for RAB32 and RAB38, promotes the exchange of GDP to GTP, converting them from an inactive GDP-bound form into an active GTP-bound form. The BLOC-3 complex plays an important role in the control of melanin production and melanosome biogenesis and promotes the membrane localization of RAB32 and RAB38 (PubMed:23084991).

Biological Process

Lysosome organization Source: ProtInc
Melanosome assembly Source: UniProtKB
Response to stimulus Source: UniProtKB-KW
Vesicle-mediated transport Source: InterPro
Visual perception Source: UniProtKB-KW

Cellular Location

BLOC-3 complex; Cytosol; Lysosome; Cytoplasm; Cytoplasmic vesicle

Involvement in disease

Hermansky-Pudlak syndrome 1 (HPS1):
A form of Hermansky-Pudlak syndrome, a genetically heterogeneous autosomal recessive disorder characterized by oculocutaneous albinism, bleeding due to platelet storage pool deficiency, and lysosomal storage defects. This syndrome results from defects of diverse cytoplasmic organelles including melanosomes, platelet dense granules and lysosomes. Ceroid storage in the lungs is associated with pulmonary fibrosis, a common cause of premature death in individuals with HPS.