Proteomics and signal transduction in the crustacean molting gland

Regulation of the molting cycle in decapod crustaceans involves2 endocrine organs: the X-organ/sinus gland (XO/SG) complexlocated in the eyestalk ganglia and the Y-organ (YO) locatedin the cephalothorax. Two neuropeptides molt-inhibiting hormone(MIH) and crustacean hyperglycemic hormone (CHH)] are producedin the XO/SG complex and inhibit ecdysteroidogenesis in theYO. Thus, YO activation is induced by eyestalk ablation (ESA),which removes the primary source of MIH and CHH. Cyclic nucleotides(cAMP and cGMP) and nitric oxide (NO) appear to mediate neuropeptidesuppression of the YO. Proteomics was used to identify potentialcomponents of signal transduction pathways ("targeted" or cell-mapproteomics) as well as assess the magnitude of protein changesin response to activation ("global" or expression proteomics)in the tropical land crab, Gecarcinus lateralis. Total proteinsin YOs from intact and ES-ablated animals were separated bytwo-dimensional gel electrophoresis and expression profileswere assessed by image analysis and gene clustering software.ESA caused a >3-fold increase in the levels of 170 proteinsand >3-fold decrease in the levels of 89 proteins; a totalof 543 proteins were quantified in total YO extracts. ESA inducedsignificant changes in the levels of 3 groups of proteins elutingfrom a phosphoprotein column and detected with phosphoproteinstaining of two-dimensional gels;