All families / PF12166
PF12166: Piezo_cap
Piezo non-specific cation channel, cap domain
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF12166: Piezo non-specific cation channel, cap domain
IPR031334: integrated entry for Piezo non-specific cation channel, cap domain
Source description
This is an extracellular domain at the C-terminus of Piezo, or FAM38 mechanosensitive non-specific cation channel proteins [InterPro reference PUB00075636,InterPro reference PUB00063634]. Piezo is a family of proteins that form mechanosensitive non-specific cation channels whose conductance is higher for Li+, intermediate for Na+ and lowest for Li+. Divalent ions except for Mn2+ permeate the channel but more slowly than monovalent ions and can reduce K+ currents [InterPro reference PUB00075636,InterPro reference PUB00063634,InterPro reference PUB00155396,InterPro reference PUB00155399]. These channels have a homotrimeric three-blade propeller-shaped structure that use a cap-motion and plug-and-latch mechanism to gate their ion-conducting pathways [InterPro reference PUB00063634,InterPro reference PUB00155396,InterPro reference PUB00155399]. Each protomer consists of 38 TM helices that form unusual non-planar blades, and an extracellular cap-like structure, the latter represented in this entry [InterPro reference PUB00063634,InterPro reference PUB00155396,InterPro reference PUB00155399,InterPro reference PUB00155398]. This domain is embedded in the centre of the trimer and may control the transmembrane constriction site suggested to act as a transmembrane gate [InterPro reference PUB00155398]. This domain adopts a distinctive beta-sandwich fold [InterPro reference PUB00063634,InterPro reference PUB00155396,InterPro reference PUB00155399,InterPro reference PUB00155397,InterPro reference PUB00155398].
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
7 verified sequence examples. FASTA
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
- 5,773
- matches
- 6,167
- proteomes
- 1,708
- taxa
- 5,363
- structures
- 30
- alphafold models
- 930
- domain architectures
- 138
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.