Hermansky-Pudlak syndrome 4 protein (HPS4)

Hermansky-Pudlak syndrome 4 protein (HPS4) is a critical component of the Biogenesis of Lysosome-related Organelles Complex-3 (BLOC-3), which serves as a guanine nucleotide exchange factor (GEF) for the Rab GTPases Rab32 and Rab38 (UniProt Q96JJ6). This protein is essential for the proper trafficking of cargo to lysosome-related organelles, including melanosomes in melanocytes and dense granules in platelets (PubMed: 22521786). Mutations in the HPS4 gene lead to Hermansky-Pudlak syndrome type 4, a rare autosomal recessive disorder characterized by oculocutaneous albinism, a bleeding diathesis, and a high risk of progressive pulmonary fibrosis (OMIM: 606682). While HPS4 is not currently targeted by any FDA-approved small molecules or biologics, it is a significant target for experimental gene therapy and molecular research aimed at restoring BLOC-3 function (NCBI Gene: 89781). Current clinical management focuses on symptomatic relief, such as managing bleeding with desmopressin or treating lung fibrosis with non-specific antifibrotics, rather than direct modulation of the HPS4 protein. The protein's role in multiple organ systems makes it a complex but vital target for future precision medicine interventions.

Other names

HPS4Light protein homologSLWBLOC3S2Hermansky-Pudlak syndrome 4 protein homolog

Not applicable as there are no currently approved drugs targeting this protein.