guca1d notes (Danio rerio, guanylate cyclase activator 1d, zGCAP4; UniProt Q6ZM98)

2026-09-28 — session log (DANRE_DUPLICATION batch 4, random TGD_tree sample)

Deep research: not available (Edison 402 Payment Required; OpenAI key invalid). Not attempted, per
instructions. Literature found by hand through Europe PMC; shared literature and name mapping in
../guca1c/guca1c-notes.md; pair analysis in ../guca1c/guca1c-bioinformatics/RESULTS.md.

Accession Q6ZM98 (TrEMBL, 185 aa), ZFIN:ZDB-GENE-040724-231 (alias gcap4), Ensembl ENSDARG00000044629, chr21.

Expression

• Cones, strongest in double and long single cones:
  PMID:15486694
  PMID:15486694
• Retina-specific by RT-PCR: PMID:15486694
• Onset 3-4 dpf with zGCAP3 and zGCAP7 (PMID:19168097).
• Adult scRNA-seq reanalysis: in 80-98% of cones of each type, 3.5-6.8 CP10K (lowest in UV cones), about a tenth
  of guca1c; rod signal at ambient level.

Function

• PMID:18777180
• Low-sensitivity group with zGCAP5 and zGCAP7 (PMID:21829700, IC50 about 400 nM vs about 30 nM for zGCAP3).
• No mutant or morphant data for guca1d.

Annotation decisions

• All Ca2+ binding rows and all GO:0008048 rows ACCEPT; GO:0009966 KEEP_AS_NON_CORE (deep NCS node, very general).