HOOK2: Hook Microtubule-Tethering Protein 2
A key regulator of endosomal trafficking and microtubule organization
Gene Information Card
| Symbol | HOOK2 |
|---|---|
| Full Name | Hook Microtubule-Tethering Protein 2 |
| Gene Type | Protein coding |
| Chromosomal Location | 19p13.13 |
| NCBI Gene ID | 29911 ncbi.nlm.nih.gov/gene/29911 |
| Ensembl ID | ENSG00000104879 |
| UniProt ID | Q96ED9 |
| OMIM ID | 607102 |
| HGNC ID | 19884 |
| Aliases | HK2, h-hook2, FLJ20209 |
Description
HOOK2 encodes a member of the hook family of proteins, which are involved in microtubule-dependent endosomal trafficking. The protein localizes to the Golgi apparatus and endosomes, and it is essential for the proper positioning of these organelles. HOOK2 interacts with the dynein-dynactin complex to mediate retrograde transport along microtubules.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Spermatogenic failure 69 | Disruption of HOOK2 leads to defects in sperm flagellum formation and male infertility | OMIM #619643 |
| Primary ciliary dyskinesia-like phenotype | Impaired microtubule tethering affects ciliary function | ClinVar |
| Cancer (pan-cancer) | Altered HOOK2 expression may influence tumor cell migration and invasion | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 15.2 | Medium |
| Brain | 8.5 | Low |
| Lung | 6.3 | Low |
| Kidney | 5.1 | Low |
| Liver | 3.8 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 12.4 | Moderate expression |
| HEK293 | 10.1 | Moderate expression |
| A549 | 7.8 | Low expression |
| K562 | 4.2 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1246C>T (p.Arg416*) | Nonsense | Rare | Loss of function; associated with spermatogenic failure |
| c.832G>A (p.Gly278Arg) | Missense | Rare | Likely damaging; affects microtubule binding |
| c.1570_1571del (p.Leu524fs) | Frameshift | Rare | Loss of function; truncation |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations in HOOK2 result in truncated proteins that fail to tether endosomes to microtubules, leading to impaired intracellular trafficking and male infertility.
Gain of Function (GOF)
No gain-of-function mutations have been reported for HOOK2.
Dominant Negative (DN)
No dominant-negative mutations have been characterized for HOOK2.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Endosomal trafficking (Reactome: R-HSA-5653656)
• Microtubule-dependent transport (Reactome: R-HSA-190236)
Protein Summary
HOOK2 is a 719-amino acid protein that contains an N-terminal microtubule-binding domain and a C-terminal hook domain. It functions as a tethering factor that links endosomes to microtubules, facilitating their retrograde transport toward the microtubule organizing center. The protein is highly expressed in testis and is critical for spermatogenesis. Loss-of-function mutations cause spermatogenic failure 69, characterized by multiple morphological abnormalities of the sperm flagella.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HOOK2 Knockout HEK293 Cell Line | EDJ-KQ8320 | Human | 29911 | Details Get a Quote |
| HOOK2 Knockout A-549 Cell Line | EDJ-KQ35560 | Human | 29911 | Details Get a Quote |
| HOOK2 Knockout HCT 116 Cell Line | EDJ-KQ35562 | Human | 29911 | Details Get a Quote |
| HOOK2 Knockout HeLa Cell Line | EDJ-KQ35563 | Human | 29911 | Details Get a Quote |
