All families / PF03381
PF03381: CDC50
LEM3 (ligand-effect modulator 3) family / CDC50 family
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF03381: LEM3 (ligand-effect modulator 3) family / CDC50 family
IPR005045: integrated entry for LEM3 (ligand-effect modulator 3) family / CDC50 family
Source description
Members of this family have been predicted to contain transmembrane helices. The family member LEM3 (P42838 (UniProtKB protein)) is a ligand-effect modulator, mutation of which increases glucocorticoid receptor activity in response to dexamethasone and also confers increased activity on other intracellular receptors including the progesterone, oestrogen and mineralocorticoid receptors. LEM3 is thought to affect a downstream step in the glucocorticoid receptor pathway. Factors that modulate ligand responsiveness are likely to contribute to the context-specific actions of the glucocorticoid receptor in mammalian cells [InterPro reference PUB00019272]. The products of genes YNR048w (P53740 (UniProtKB protein)), YNL323w (P42838 (UniProtKB protein)) and YCR094w (P25656 (UniProtKB protein)) (CDC50) show redundancy of function and are involved in regulation of transcription via CDC39 [InterPro reference PUB00019273]. CDC39 (also known as NOT1) is normally a negative regulator of transcription either by affecting the general RNA polymerase II machinery or by altering chromatin structure [InterPro reference PUB00019275]. One function of CDC39 is to block activation of the mating response pathway in the absence of pheromone, and mutation causes arrest in G1 by activation of the pathway [InterPro reference PUB00019274]. It may be that the cold-sensitive arrest in G1 noticed in CDC50 mutants [InterPro reference PUB00019273] may be due to inactivation of CDC39. The effects of LEM3 on glucocorticoid receptor activity may also be due to effects on transcription via CDC39.
Evidence and references
- InterPro entry and its literature references. PUB identifiers are internal InterPro references, not PubMed identifiers. Unresolved citations link to the originating entry.
- Frozen description source: InterPro/Pfam API
Source descriptions and links are provenance, not independent functional validation.
Evidence counts: not scored.
Curated functional assertions
No curated functional assertions supplied.
Protein sequence examples
6 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| H2L0H3 | CDC50 family protein chat-1 Caenorhabditis elegans | 348 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| P25656 | Phospholipid-transporting ATPase accessory subunit CDC50 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) | 391 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| P42838 | Phospholipid-transporting ATPase accessory subunit LEM3 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) | 414 aa; version 1 UniProt 2026_03 | UNIPROT FETCH2 sibling references |
| Q3MIR4 | Cell cycle control protein 50B Homo sapiens | 351 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR |
| Q8VEK0 | Cell cycle control protein 50A Mus musculus | 364 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q9NV96 | Cell cycle control protein 50A Homo sapiens | 361 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
Pfam membership is not functional evidence. Whole-protein sequences do not establish domain boundaries. A coverage gap here is not absence from UniProt.
Sequences and metadata: UniProt Consortium, CC BY 4.0.
Domain matches
No residue-level domain match evidence is available in this build. Structure and AlphaFold counters do not supply coordinates or establish function.
Snapshot counters
- proteins
- 8,587
- matches
- 8,770
- proteomes
- 3,431
- taxa
- 9,045
- structures
- 62
- alphafold models
- 7,263
- domain architectures
- 147
Classification basis
pfam previous unknown name
No scoring reasons supplied.
Related Mech records
This family joined the worklist after the frozen cross-Mech scan, so other Mechs were not searched for it. Missing links here are not evidence that other Mechs lack it; rows shown come from mentions of a former DUF/UPF name.
No cross-Mech examples are present in the supplied snapshot.
Curation history and reviews
No retained curation events supplied.
No retained review supplied.
Record source
Status and evidence
- Seed status
- A name-based classification of frozen InterPro/Pfam metadata. UNKNOWN CANDIDATE means the metadata explicitly says the function is unknown. KNOWN HISTORICAL DUF means a DUF name matched without that wording; this heuristic is not proof of a known function and does not establish experimental characterization. EX DUF means Pfam renamed the family away from a DUF/UPF name, as recorded in Pfam's previous identifiers; a rename usually follows published work on some members but is naming history, not proof of function for every member. Some EX DUF families' current names or descriptions still say the function is unknown; their classification basis lists this, and scoring does not treat them as characterized. FALSE POSITIVE TEXT HIT means the naming rules did not match.
- Characterization
- A separate evidence-scoring result. UNSCORED means no score has been calculated; it is not evidence that the family lacks a known function. Missing scores are not negative evidence. PARTIALLY CHARACTERIZED has partial support; KNOWN HISTORICAL DUF can inherit the seed label or reflect a known-function signal. Neither label implies experimental validation.
- Evidence counts
- Source-specific signals, not unique proteins, publications, or confidence scores. Known counts Rhea reactions and experimentally supported GO molecular-function annotations. Partial counts functional/domain assignments. Context counts structural, environmental, orthology, interaction and neighborhood signals; context alone does not assign function. Repeated annotations may not be independent.
- Curation status
- Reported separately from seed classification and characterization. SNAPSHOT ONLY means no curated metadata was supplied for this build. SEEDED denotes a source-derived record, not an expert-reviewed functional claim.
- Missing counts
- Not available means the source did not supply that counter. A zero is a reported count. Not scored means evidence counts are unavailable.