CAMTA1 evidence and functional review

CAMTA1 is a nuclear DNA-dependent transcriptional regulator with a conserved CG-1 domain, a TIG domain, ankyrin repeats and IQ motifs. Human reporter experiments establish transcriptional activation capacity. Human loss-of-function rearrangements connect CAMTA1 to congenital cerebellar ataxia with or without intellectual disability; mouse studies provide a mechanistic context for neuronal maintenance. A separate positive influence on NFAT signaling is supported in cultured human cells, with its intervening mechanism unresolved.

Identity and products

The normal UniProt record is human Q9Y6Y1, 1,673 amino acids, sequence version 4, CRC64 008AA6A906374C00. Its four machine-fetched products are preserved: Q9Y6Y1-1; Q9Y6Y1-2 (VSP_035936, VSP_035937); Q9Y6Y1-3 (VSP_043842, VSP_043843); and Q9Y6Y1-4 (VSP_046358, VSP_046359). Products 3 and 4 lack most of the canonical sequence. The full-length domain architecture and activity are not asserted independently for every short product.

Evidence boundaries

Annotation and core decisions

All ten original assertion objects and all four products remain exact. Six assertions are accepted, generic DNA binding is refined to GO:0003700, two assertions remain undecided, and the experimental NFAT-regulatory process is retained as non-core. No NEW annotation is proposed.

The official definitions of GO:0003700 and GO:0003712 distinguish intrinsic DNA-dependent regulation from regulation through a DNA-binding transcription-factor partner. Human activation evidence, conserved domains and mammalian molecular experiments support one DNA-binding transcription-factor core in the nucleus, linked to positive RNA polymerase II transcriptional regulation. The core does not assert a characterized human promoter repertoire, direct calcium sensing, calmodulin binding, a particular protein complex, or NFAT catalytic activity.

The coregulator IBA is plausible and remains UNDECIDED because its distinct partner mechanism and precise PTN000596526 IBD placement were not recovered. DNA binding does not disprove coregulation. The donor count and mixture of descendant species are not arguments against an ancestral assertion, and no target-specific loss is claimed. Broader IBA DNA-binding, nuclear and transcriptional assertions are retained as coherent inherited functions. The cytoplasm IEA remains UNDECIDED because the relevant localization details could not be accessed; a nuclear activity does not exclude a cytoplasmic pool.

Access and provenance

Four additional PMID caches were produced by one normal hosted fetch and imported by ROOT after archive and source checks. Their abstract-only flags are preserved; external primary-text access is recorded separately. Existing publications 34499028, 21760942 and 23581962 remain protected and are not used as load-bearing evidence here. Tumor fusion biology and plant family results are not conflated with normal human CAMTA1 function. The GO-CAM index contained no CAMTA1 symbol match; this is a limited index observation, not proof that no relevant model exists.

The isolated normal Falcon research attempt and its perplexity-lite fallback both failed because of connectivity; no report was produced. This manual synthesis is not a provider report. The normal validator reported zero warnings and the status checker expected COMPLETE; that workflow status does not erase the two undecided assertions or the need for a distinct scientific peer. Canonical application still requires ROOT approval and normal checks. Source files and source caches are unchanged.

Follow-up: native CAMTA promoter evidence

PMID:34499028, Neuronal calmodulin levels are controlled by CAMTA transcription factors, is now used as experimental family evidence. This supersedes the earlier access note that set this existing cache aside. Its full cached Introduction, Results and figure captions, Discussion, and Methods were read for this follow-up; the source cache itself remains unchanged.

In C. elegans, a CRISPR knock-in CAMT-1a::GFP strain was used for ChIP-seq with input and mock-pulldown controls. The experiments identify three enriched regions approximately 6.3, 4.8 and 2.2 kb upstream of the cmd-1 translation start. The tested single or double promoter-region deletions leave aggregation and O2 responses similar to controls. Deleting all three regions produces locomotory and chemotaxis defects resembling camt-1 loss; extra neuronal CMD-1 rescues these defects. The promoter experiment therefore connects native occupancy with cis-regulatory function. ChIP alone does not distinguish direct DNA contacts from tethered occupancy, and the Discussion reports that de novo motif analysis did not find coincident motifs, while noting overlap with mouse CAMTA motifs. The integrated CG-1, human transactivation and mammalian DNA-recognition evidence remains the basis for the human DNA-binding transcription-factor refinement; the worm result strengthens it without being mislabeled a human experiment.

The official GO definitions distinguish DNA-binding transcription-factor activity (GO:0003700) from regulation through a DNA-binding transcription-factor partner (GO:0003712). These mechanisms can coexist. Neither native promoter occupancy nor the new worm experiments prove that human CAMTA1 lacks coregulator activity. The exact frozen coregulator row contains PTN000596526, PomBase:SPAC26H5.05 and UniProtKB:O94983. Contrary to one premise of the external review, WB:WBGene00020251 is present in other CAMTA1 IBA rows but not this coregulator row. Reading experimental family evidence does not reconstruct the PAINT node placement.

A bounded check of the literal source identities confirms PomBase SPAC26H5.05 as Mga2 and UniProt O94983 as CAMTA2. The primary abstract of Song et al., The transcriptional coactivator CAMTA2 stimulates cardiac growth by opposing class II histone deacetylases (PubMed 16678093), reports CAMTA-associated activation through the DNA-binding partner Nkx2-5. This supports the plausibility of a separate family coregulator mechanism; its full paper and exact PAINT placement were not reconstructed here. It is not used to manufacture a human CAMTA1 partner annotation. The two existing actions therefore remain MODIFY and UNDECIDED, with the uncertainty now specifying the unresolved human mechanism and ancestral placement rather than overlooking the available worm study.

The same worm paper studies potential IQ-dependent feedback at elevated calmodulin levels, but explicitly treats the binding model and physiological feedback as unresolved. It does not establish direct human CAMTA1 calcium or calmodulin binding. No new molecular-function or process assertion is introduced. The 2024 eLife correction was read in full: it adds Saliha E Sönmez as an author for Drosophila retinal imaging and makes no change to the CAMT-1 promoter experiments or their interpretation.

Two optional review concerns were checked against external primary material already retained with the original review. The published Figure 4 caption in PMID:23853098 explicitly assigns the reporter assay to 293A and the CAMTA1/PTBP1 knockdown dephosphorylation assay in panel B to 293T; that accurate distinction is retained. The primary Results of PMID:25049392 explicitly report CAMTA1 K141E loss of DNA binding, so the statement is retained with its existing external-access provenance despite the canonical cache being abstract-only. No claim is weakened solely because it was checked outside the cache.

All ten machine assertion objects, their actions, four products, original references and supporting quotations, and the single core function remain unchanged. One already-existing reference and two short verbatim anchors are added; no source or history file is rewritten. No new normal fetch or provider research attempt is needed for this bounded follow-up.