BLOC1S3: Biogenesis of Lysosomal Organelles Complex 1 Subunit 3
A key component in lysosome-related organelle biogenesis, associated with Hermansky-Pudlak syndrome type 8
Gene Information Card
| Symbol | BLOC1S3 |
|---|---|
| Full Name | Biogenesis of Lysosomal Organelles Complex 1 Subunit 3 |
| Gene Type | Protein coding |
| Chromosomal Location | 19q13.32 |
| NCBI Gene ID | 388552 ncbi.nlm.nih.gov/gene/388552 |
| Ensembl ID | ENSG00000189114 |
| UniProt ID | Q6QNY0 |
| OMIM ID | 609762 |
| HGNC ID | 20914 |
| Aliases | HPS8, BLOS3, MGC26594 |
Description
BLOC1S3 encodes a subunit of the biogenesis of lysosomal organelles complex 1 (BLOC-1), which is involved in the formation of lysosome-related organelles such as melanosomes and platelet dense granules. Mutations in this gene cause Hermansky-Pudlak syndrome type 8 (HPS8), characterized by oculocutaneous albinism, bleeding diathesis, and sometimes pulmonary fibrosis or granulomatous colitis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hermansky-Pudlak syndrome 8 (HPS8) | Loss-of-function mutations in BLOC1S3 disrupt BLOC-1 complex assembly, impairing melanosome and platelet dense granule biogenesis. | OMIM #614077; ClinVar; multiple case reports |
| Albinism, oculocutaneous, with bleeding diathesis | Same mechanism as HPS8; defective organelle trafficking leads to hypopigmentation and platelet storage pool deficiency. | OMIM; literature review |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lung | 5.2 | Low |
| Spleen | 4.8 | Low |
| Testis | 3.9 | Low |
| Brain | 2.1 | Not detected |
| Liver | 1.5 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 3.0 | Moderate expression in kidney-derived line |
| K562 | 2.5 | Low expression in leukemia line |
| HeLa | 1.8 | Low expression in cervical cancer line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.149G>A (p.Trp50*) | Nonsense | Rare | Loss of function; premature stop codon |
| c.334C>T (p.Arg112*) | Nonsense | Rare | Loss of function; premature stop codon |
| c.1A>G (p.Met1?) | Start loss | Rare | Loss of function; translation initiation failure |
Mutation functional classification
Loss of Function (LOF)
All reported BLOC1S3 mutations are loss-of-function (nonsense, frameshift, start loss), leading to truncated or absent protein, disrupting BLOC-1 complex integrity.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported; HPS8 is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • BLOC-1 complex (GO:0031083) | • melanosome organization (GO:0032438) |
| • platelet dense granule organization (GO:0030168) | • cytoplasm (GO:0005737) |
| • transport vesicle (GO:0030133) |
Pathways
• Hermansky-Pudlak syndrome (HPS) pathway
• Lysosome-related organelle biogenesis
• BLOC-1 mediated cargo sorting
Protein Summary
BLOC1S3 is a 203-amino-acid protein (UniProt Q6QNY0) that localizes to the cytoplasm and is a stable component of the BLOC-1 complex. It is essential for the biogenesis of lysosome-related organelles, including melanosomes and platelet dense granules. Loss of BLOC1S3 leads to misrouting of cargo proteins such as tyrosinase and CD63.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| BLOC1S3 Knockout HEK293 Cell Line | EDJ-KQ12539 | Human | 388552 | Details Get a Quote |
| BLOC1S3 Knockout HCT 116 Cell Line | EDJ-KQ40242 | Human | 388552 | Details Get a Quote |
| BLOC1S3 Knockout A-549 Cell Line | EDJ-KQ41533 | Human | 388552 | Details Get a Quote |
| BLOC1S3 Knockout HeLa Cell Line | EDJ-KQ41535 | Human | 388552 | Details Get a Quote |
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