Guanylate Cyclase Activator 1B, Retina (GUCA1B)

GUCA1B is a calcium-binding protein that activates photoreceptor guanylate cyclases. This gene may have arisen due to a gene duplication event since there is a highly similar gene clustered with it on chromosome 6. Mutations in this gene can cause a form of retinitis pigmentosa.Guanylate cyclase activating proteins are related Ca(2+)-binding proteins that activate photoreceptor guanylate cyclase(s). Surguchov et al. (1997) showed by PCR analysis that the GUCA1B gene, termed GCAP2 by the authors, is arranged in a tail-to-tail array with the GUCA1A gene. Northern blot analysis revealed a 2.2-kb GUCA1B mRNA species that is detectable only in the retina. Surguchov et al. (1997) concluded that the closely related gene structures and locations of GUCA1A and GUCA1B are consistent with a gene duplication event.