| Category | NHR-47 summary |
|---|---|
| Gene / protein identifiers | **Gene name:** nhr-47; **Systematic name / ORF:** C24G6.4; **UniProt accession:** Q17370; **Reported synonym:** csr-1 *(must not be confused with the unrelated CSR-1 Argonaute gene)* (pqac-00000004) |
| Organism | *Caenorhabditis elegans* (pqac-00000004) |
| Protein family | Nuclear hormone receptor (NHR); HNF4-like **supplementary NHR** within the nematode-expanded receptor family (pqac-00000012, pqac-00000014) |
| Core domains | HNF4-like DNA-binding domain and nuclear receptor ligand-binding domain; domain architecture is consistent with a canonical ligand-regulated transcription factor in the NHR superfamily (family context from pqac-00000012, pqac-00000014) |
| Predicted molecular function | Putative ligand-dependent transcription factor / transcriptional regulator responding to lipophilic small molecules, inferred from its NHR family membership and HNF4-like architecture (pqac-00000012, pqac-00000014) |
| Direct experimental evidence: steroid responsiveness | **Estradiol-induced upregulation:** 10 μM estradiol increased **nhr-47** expression **3.4-fold** in microarray analysis, identifying it as an estradiol-responsive NHR (pqac-00000004, pqac-00000005, pqac-00000023) |
| Direct experimental evidence: C. elegans phenotype | Published RNAi experiments in *C. elegans* reported **no observable phenotype** for **nhr-47**, indicating either redundancy, condition-specific function, or weak effect under standard assay conditions (reported in Ciche et al. summarizing prior RNAi studies) (pqac-00000025) |
| Cross-species ortholog evidence | RNAi of the *Heterorhabditis bacteriophora* ortholog **Hba-nhr-47** usually caused **no obvious phenotype**, with only **3–12% sterility** in some trials, supporting a subtle or context-dependent role (pqac-00000024, pqac-00000025) |
| Putative biological processes | Likely part of an **estrogen-sensitive gene network** associated with **vitellogenesis**, lipid availability, and broader metabolic/endocrine responses; however, no direct downstream targets have been established for nhr-47 itself (pqac-00000004, pqac-00000005, pqac-00000023) |
| Predicted subcellular localization | **Nucleus** (inferred), because NHR-47 contains an HNF4-like DNA-binding domain and belongs to a family of nuclear transcription factors; no nhr-47-specific localization study was found (pqac-00000012, pqac-00000014) |
| Evolutionary context | Member of the nematode-specific expansion of HNF4-related receptors: *C. elegans* has **284** NHRs overall, including **269 supplementary NHRs (supnrs)** derived from an ancient HNF4-like ancestor; this expansion is far larger than in humans or flies (pqac-00000011, pqac-00000012, pqac-00000014, pqac-00000019) |
| Broader functional context of family | HNF4-like C. elegans NHRs commonly regulate **metabolism, fat storage/catabolism, xenobiotic responses, and physiological adaptation**, often in modular gene-regulatory networks; nhr-47 is therefore plausibly metabolic/endocrine, though not directly characterized (pqac-00000011, pqac-00000012, pqac-00000018) |
| Characterization status | **Poorly characterized / orphan receptor.** The literature provides direct evidence for steroid-responsive expression but little mechanistic information on ligands, tissue expression, target genes, or physiological necessity under standard conditions (pqac-00000005, pqac-00000023, pqac-00000025) |


*Table: This table consolidates verified identifiers, family/domain assignment, and the limited direct experimental evidence available for C. elegans NHR-47. It is useful as a high-confidence quick reference because the gene is sparsely characterized and easily confused with unrelated genes sharing similar names.*