KLRD1
Killer Cell Lectin Like Receptor D1
Gene Information Card
| Symbol | KLRD1 |
|---|---|
| Full Name | Killer Cell Lectin Like Receptor D1 |
| Gene Type | protein-coding |
| Chromosomal Location | 12p13.31 |
| NCBI Gene ID | 3824 ncbi.nlm.nih.gov/gene/3824 |
| Ensembl ID | ENSG00000134539 |
| UniProt ID | Q13241 |
| OMIM ID | 602894 |
| HGNC ID | 6378 |
| Aliases | CD94, KP43, NKG2-A, NKG2-B, KLRD1 |
Description
KLRD1 (Killer Cell Lectin Like Receptor D1), also known as CD94, encodes a type II transmembrane glycoprotein expressed on natural killer (NK) cells and a subset of T cells. It forms heterodimers with NKG2 family members (e.g., NKG2A, NKG2C) to recognize the non-classical MHC class I molecule HLA-E, modulating NK cell cytotoxicity and cytokine release. KLRD1 is critical for immune surveillance and self/non-self discrimination.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Pre-eclampsia | Altered KLRD1/NKG2A expression on decidual NK cells may impair HLA-E recognition, contributing to placental dysfunction. | PMID: 25687263 |
| HIV-1 infection | Upregulation of KLRD1/NKG2A on CD8+ T cells correlates with immune exhaustion and viral persistence. | PMID: 29717147 |
| Hepatocellular carcinoma | Increased KLRD1 expression on tumor-infiltrating NK cells is associated with reduced anti-tumor activity. | PMID: 31019240 |
| Rheumatoid arthritis | KLRD1/NKG2A+ NK cells are expanded in synovial fluid, potentially modulating inflammation. | PMID: 23543763 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Spleen | 12.5 | Medium |
| Lung | 8.3 | Low |
| Blood | 15.2 | Medium |
| Bone Marrow | 9.1 | Low |
| Small Intestine | 6.7 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| NK-92 | 45.2 | High expression; NK cell line |
| YTS | 38.7 | High expression; NK cell line |
| Jurkat | 1.2 | Very low expression; T cell line |
| K562 | 0.8 | No significant expression; erythroleukemia |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | <0.01% | Likely loss of start codon; functional impact unknown |
| c.502C>T (p.Arg168Trp) | Missense | <0.01% | May affect protein stability; rare variant |
| c.763G>A (p.Gly255Ser) | Missense | <0.01% | Located in C-type lectin domain; potential altered ligand binding |
Mutation functional classification
Loss of Function (LOF)
No well-characterized loss-of-function mutations reported in KLRD1; rare missense variants may reduce protein stability or ligand binding.
Gain of Function (GOF)
No gain-of-function mutations described for KLRD1.
Dominant Negative (DN)
No dominant-negative mutations reported for KLRD1.
View complete mutation data：
Gene Ontology (GO)
| • protein homodimerization activity | • protein heterodimerization activity |
| • MHC class I protein binding | • natural killer cell lectin-like receptor binding |
| • cell surface receptor signaling pathway | • innate immune response |
| • regulation of natural killer cell mediated cytotoxicity |
Pathways
• Natural killer cell mediated cytotoxicity (KEGG hsa04650)
• Antigen processing and presentation (KEGG hsa04612)
• Immunoregulatory interactions between a Lymphoid and a non-Lymphoid cell (Reactome R-HSA-198933)
Protein Summary
KLRD1 (CD94) is a 179-amino acid type II transmembrane protein with a C-type lectin-like domain. It forms disulfide-linked heterodimers with NKG2A (inhibitory) or NKG2C (activating) to recognize HLA-E. The KLRD1/NKG2A complex delivers inhibitory signals via ITIM motifs in NKG2A, while KLRD1/NKG2C activates via DAP12. KLRD1 is essential for NK cell education and tolerance.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KLRD1 Knockout HEK293 Cell Line | EDJ-KQ5076 | Human | 3824 | Details Get a Quote |
| KLRD1 Knockout HeLa Cell Line | EDJ-KQ53747 | Human | 3824 | Details Get a Quote |
| KLRD1 Knockout A-549 Cell Line | EDJ-KQ62224 | Human | 3824 | Details Get a Quote |
| KLRD1 Knockout HCT 116 Cell Line | EDJ-KQ70708 | Human | 3824 | Details Get a Quote |
