PUBLICATION

Differential calcium signaling by cone specific guanylate cyclase-activating proteins from the zebrafish retina

Authors
Scholten, A., and Koch, K.W.
ID
ZDB-PUB-110811-37
Date
2011
Source
PLoS One   6(8): e23117 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Enzyme Activation
  • DNA Primers
  • Retina/metabolism*
  • Guanylate Cyclase/metabolism
  • Chromatography, High Pressure Liquid
  • Protein Binding
  • Spectrometry, Fluorescence
  • Base Sequence
  • Zebrafish
  • Polymerase Chain Reaction
  • Calcium Signaling*
  • Protein Conformation
  • Mutagenesis, Site-Directed
  • Cloning, Molecular
  • Hydrolysis
  • Animals
  • Calcium/metabolism
  • Guanylate Cyclase-Activating Proteins/genetics
  • Guanylate Cyclase-Activating Proteins/metabolism
  • Guanylate Cyclase-Activating Proteins/physiology*
(all 20)
PubMed
21829700 Full text @ PLoS One
Abstract
Zebrafish express in their retina a higher number of guanylate cyclase-activating proteins (zGCAPs) than mammalians pointing to more complex guanylate cyclase signaling systems. All six zGCAP isoforms show distinct and partial overlapping expression profiles in rods and cones. We determined critical Ca2+-dependent parameters of their functional properties using purified zGCAPs after heterologous expression in E.coli. Isoforms 1–4 were strong, 5 and 7 were weak activators of membrane bound guanylate cyclase. They further displayed different Ca2+-sensitivities of guanylate cyclase activation, which is half maximal either at a free Ca2+ around 30 nM (zGCAP1, 2 and 3) or around 400 nM (zGCAP4, 5 and 7). Zebrafish GCAP isoforms showed also differences in their Ca2+/Mg2+-dependent conformational changes and in the Ca2+-dependent monomer-dimer equilibrium. Direct Ca2+-binding revealed that all zGCAPs bound at least three Ca2+. The corresponding apparent affinity constants reflect binding of Ca2+ with high (d100 μM), medium (0.1–5 μM) and/or low (e5 μM) affinity, but were unique for each zGCAP isoform. Our data indicate a Ca2+-sensor system in zebrafish rod and cone cells supporting a Ca2+-relay model of differential zGCAP operation in these cells.
Genes / Markers
Figures
No images available
Expression
Phenotype
No data available
Mutations / Transgenics
No data available
Human Disease / Model
No data available
Sequence Targeting Reagents
No data available
Fish
Antibodies
Orthology
Engineered Foreign Genes
No data available
Mapping
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Citation
Scholten, A., and Koch, K.W. (2011) Differential calcium signaling by cone specific guanylate cyclase-activating proteins from the zebrafish retina. PLoS One. 6(8):e23117.