CASP-like protein 4C1 (AtCASPL4C1, At3g55390) is a small tetraspan (four-transmembrane) plasma-membrane protein of the CASP-like (CASPL) subfamily of the MARVEL-related Casparian strip membrane domain protein family (group 4C). It is the Arabidopsis ortholog of a cold-induced watermelon CASP-like gene (ClCASPL). AtCASPL4C1 is cold-inducible and broadly expressed, and acts as a negative regulator of growth, biomass and flowering time while modulating cold tolerance (knockout plants show faster growth, increased biomass and elevated cold tolerance without Casparian strip defects), indicating a role beyond root Casparian strip formation, possibly in vascular tissue. The protein localizes to the plasma membrane; no specific molecular function has been characterized.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000044 | ACCEPT | Summary: Correct, well-supported plasma-membrane localization for this multi-pass CASP-like protein. Reason: UniProt annotates a multi-pass cell-membrane protein and the localization is independently confirmed experimentally (IDA, PMID:24920445). Supporting Evidence: file:ARATH/CASPL4C1/CASPL4C1-uniprot.txt SUBCELLULAR LOCATION: Cell membrane |
| GO:0003674 molecular_function | ND GO_REF:0000015 | ACCEPT | Summary: Root-level placeholder reflecting that no specific molecular function has been characterized. Reason: No catalytic or transport activity is known for this CASP-like scaffold protein; the ND root annotation accurately reflects the absence of molecular-function data. Supporting Evidence: file:ARATH/CASPL4C1/CASPL4C1-goa.tsv molecular_function |
| GO:0005575 cellular_component | ND GO_REF:0000015 | ACCEPT | Summary: Root-level cellular_component placeholder; uninformative given the established plasma-membrane localization. Reason: An ND root placeholder; it conflicts with nothing but adds no information beyond the plasma-membrane annotation. Supporting Evidence: file:ARATH/CASPL4C1/CASPL4C1-goa.tsv cellular_component |
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Download this section (compressed HTML)Q: Through what molecular mechanism does AtCASPL4C1 restrain growth and modulate cold tolerance, and is its action localized to vascular tissue?
Experiment: Tissue-resolved expression and cold-response profiling of AtCASPL4C1, with growth/biomass/cold-tolerance phenotyping of knockout and overexpression lines and identification of interacting partners.
Type: genetic perturbation and stress phenotyping
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