CHML Gene - Rab Escort Protein 2
Comprehensive guide to CHML (CHM Like Rab Escort Protein) gene, its function, associated diseases, expression, and mutations.
Gene Information Card
| Symbol | CHML |
|---|---|
| Full Name | CHM Like Rab Escort Protein |
| Gene Type | protein-coding |
| Chromosomal Location | 1q43 |
| NCBI Gene ID | 1122 ncbi.nlm.nih.gov/gene/1122 |
| Ensembl ID | ENSG00000116285 |
| UniProt ID | P26374 |
| OMIM ID | 118825 |
| HGNC ID | 1942 |
| Aliases | REP2, Rab escort protein 2 |
Description
The CHML gene encodes Rab escort protein 2 (REP2), which is essential for the prenylation and membrane targeting of Rab GTPases. REP2 forms a complex with Rab geranylgeranyltransferase (GGTase II) to facilitate the addition of geranylgeranyl groups to Rab proteins, enabling their proper localization and function in vesicular trafficking. Mutations in CHML are associated with choroideremia-like retinal degeneration.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Choroideremia | Deficiency in Rab escort protein 2 disrupts Rab prenylation, impairing vesicular transport in retinal pigment epithelium and photoreceptors, leading to degeneration. | OMIM #303100, ClinVar |
| Retinitis Pigmentosa | Similar mechanism as choroideremia; reduced REP2 function affects photoreceptor survival. | ClinVar, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 15.2 | Low |
| Retina | 12.8 | Low |
| Brain | 10.5 | Low |
| Heart | 8.3 | Low |
| Liver | 6.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK 293 | 18.4 | Embryonic kidney cells |
| HeLa | 14.7 | Cervical cancer cells |
| K562 | 11.2 | Leukemia cells |
| A549 | 9.8 | Lung cancer cells |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.499C>T (p.Arg167*) | Nonsense | Rare | Loss of function; truncated protein |
| c.940G>A (p.Gly314Arg) | Missense | Rare | Impaired REP2 activity |
| c.1234delA | Frameshift | Rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations lead to truncated or absent REP2, disrupting Rab prenylation.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Not described for CHML.
View complete mutation data：
Gene Ontology (GO)
| • Rab GTPase binding | • Rab geranylgeranyltransferase activity |
| • protein prenylation | • intracellular protein transport |
| • vesicle-mediated transport |
Pathways
• Rab geranylgeranylation
• Vesicular transport
• Protein prenylation
Protein Summary
Rab escort protein 2 (REP2) is a 663-amino acid protein that binds newly synthesized Rab GTPases and presents them to Rab geranylgeranyltransferase for prenylation. REP2 then escorts the prenylated Rab to the target membrane. It is highly expressed in retina and testis, and its dysfunction leads to retinal degeneration.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CHML Knockout HEK293 Cell Line | EDJ-KQ3573 | Human | 1122 | Details Get a Quote |
| CHML Knockout A-549 Cell Line | EDJ-KQ26759 | Human | 1122 | Details Get a Quote |
| CHML Knockout HCT 116 Cell Line | EDJ-KQ26760 | Human | 1122 | Details Get a Quote |
| CHML Knockout HeLa Cell Line | EDJ-KQ26761 | Human | 1122 | Details Get a Quote |
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