Title

Cloning and Characterization of a Calmodulin Gene (CaM) in Crayfish Procambarus clarkii and Expression During Molting

Document Type

Article

Publication Date

3-2009

Abstract

Calmodulin (CaM) is a highly conserved calcium (Ca2+) binding protein that transduces Ca2+ signals into downstream effects influencing a range of cellular processes, including Ca2+ homeostasis. The present study explores CaM expression when Ca2+ homeostasis is challenged during the mineralization cycle of the freshwater crayfish (Procambarus clarkii). In this paper we report the cloning of a CaM gene from axial abdominal crayfish muscle (referred to as pcCaM). The pcCaM mRNA is ubiquitously expressed but is far more abundant in excitable tissue (muscle, nerve) than in any epithelia (gill, antennal gland, digestive) suggesting that it plays a greater role in the biology of excitation than in epithelial ion transport. In muscle cells the pcCaM was colocalized on the plasma membrane with the Ca2+ ATPase (PMCA) known to regulate intracellular Ca2+ through basolateral efflux. While PMCA exhibits a greater upregulation in epithelia (than in non-epithelial tissues) during molting stages requiring transcellular Ca2+ flux (pre- and postmolt compared with intermolt), expression of pcCaM exhibited a uniform increase in epithelial and non-epithelial tissues alike. The common increase in expression of CaM in all tissues during pre- and postmolt stages (compared with intermolt) suggests that the upregulation is systemically (hormonally) mediated. Colocalization of CaM with PMCA confirms physiological findings that their regulation is linked.

Journal

Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology

Volume

152

Issue

3

First Page

216

Last Page

225