Molecular cloning and characterization of a sarco/endoplasmic reticulum Ca2+ ATPase (SERCA) from Y-organs of the blue crab (Callinectes sapidus)

Academic Article

Abstract

  • Existing data indicate that a Ca signal stimulates ecdysteroid hormone production by crustacean molting glands (Y-organs). Ca signaling is dependent on a tightly regulated Ca gradient, with intracellular free Ca maintained at a low basal level (typically sub-micromolar). This is achieved through the action of proteins intrinsic to the plasma membrane and the membranes of organelles. One such protein, the sarco/endoplasmic reticulum Ca ATPase (SERCA), pumps Ca from cytosol to the lumen of the endoplasmic reticulum. As a step toward understanding Ca -mediated regulation of ecdysteroidogenesis, we have begun investigating Ca transport proteins in Y-organs. In studies reported here, we used a PCR-based strategy to clone from Y-organs of the blue crab (Callinectes sapidus) a cDNA encoding a putative SERCA protein. The cloned Cas-SERCA cDNA (3806 bp) includes a 3057-bp open reading frame that encodes a 1019-residue protein (Cas-SERCA). The conceptually translated protein has a predicted molecular mass of 111.42 × 10 and contains all signature domains of an authentic SERCA, including ten transmembrane domains and a phosphorylation site at aspartate 351. A homology model of Cas-SERCA closely resembles models of related SERCA proteins. Phylogenetic analysis shows Cas-SERCA clusters with SERCA proteins from other arthropods. An assessment of tissue distribution indicates the Cas-SERCA transcript is widely distributed across tissues. Studies using quantitative PCR showed Cas-SERCA transcript abundance increased significantly in Y-organs activated by eyestalk ablation, a pattern consistent with the hypothesis that Cas-SERCA functions to maintain Ca homeostasis in Y-organs. 2+ 2+ 2+ 2+ 2+ 2+ 2+ 2+ 3 2+
  • Published In

  • Gene  Journal
  • Digital Object Identifier (doi)

    Author List

  • Roegner ME; Chen HY; Watson RD
  • Start Page

  • 12
  • End Page

  • 21
  • Volume

  • 673