Disease relevance of Guca1b

• GCAP2 was also found in amacrine and ganglion cells of the inner retina [1].

High impact information on Guca1b

• This feedback loop was disrupted in mouse rods lacking guanylate cyclase activating proteins GCAP1 and GCAP2 (GCAPs(-/-)) [2].
• Guanylate cyclase-activating protein (GCAP) 1 rescues cone recovery kinetics in GCAP1/GCAP2 knockout mice [3].
• We have found that unlike its homolog, GCAP-1, the C terminus of GCAP-2 undergoes phosphorylation by cyclic nucleotide-dependent protein kinases (CNDPK) present in the retinal extract and rapid dephosphorylation by the protein phosphatase PP2C present in the retina [4].
• The Ca(2+)-dependent conformational changes in GCAP-2 affect the areas around Glu(62) residue in the entering helix of EF-hand 2, the areas proximal to the exiting helix of EF-hand 3, and Glu(136)-Glu (138) between EF-hand 3 and EF-hand 4 [4].
• Immunocytochemistry showed that both GCAP genes are expressed in retinal photoreceptor cells, but GCAP2 was nearly undetectable in cones [1].

Biological context of Guca1b

• GCAP2 expressed in GCAPs-/- rods restored maximal light-induced GC activity but did not restore normal flash response kinetics [5].
• Ca(2+)-dependent conformational changes in guanylyl cyclase-activating protein 2 (GCAP-2) revealed by site-specific phosphorylation and partial proteolysis [4].
• Identification of both GCAPs in synaptic regions, and of GCAP2 in the inner retina suggest roles of these Ca-binding proteins in addition to regulation of phototransduction [1].
• METHODS: The GCAP1 and GCAP2 genes were cloned from genomic libraries and sequenced [1].
• PURPOSE: To identify gene arrangement, chromosomal localization, and expression pattern of mouse guanylate cyclase activating proteins GCAP1 and GCAP2, retina-specific Ca2+-binding proteins, and photoreceptor guanylate cyclase activators [1].

Anatomical context of Guca1b

• To investigate the extent of this phenomenon we examined additional photoreceptor proteins that might undergo light-driven translocation, focusing on three Ca(2+)-binding proteins, recoverin and guanylate cyclase activating proteins 1 (GCAP1) and GCAP2 [6].
• Inactivation of the CNDPK phosphorylation site in GCAP-2 by substitutions S201G or S201D, as well as phosphorylation or thiophosphorylation of Ser(201), had little effect on the ability of GCAP-2 to regulate retGC in reconstituted membranes in vitro [4].

Associations of Guca1b with chemical compounds

• At the same time, Ca(2+) strongly inhibited phosphorylation of the wild-type GCAP-2 by retinal CNDPK but did not affect phosphorylation of a constitutively active Ca(2+)-insensitive GCAP-2 mutant [4].

Analytical, diagnostic and therapeutic context of Guca1b

• The expression of GCAP1 and GCAP2 in mouse retinal tissue was determined by immunocytochemistry [1].

References