A 18-aa peptide sequence, mapping within cytoplasmic N-terminus of rat CaT-1/ECAC2 (1) was synthesized, coupled to KLH.
Calcium (Ca+2 or Ca) is the most abundant cation and it is required for many physiological activities such as bone formation and it acts as a second messenger in signal transduction. However only 1% of Ca is present in ionic form in biological fluids. Ca concentration is regulated by calcitropic hormones that act on bone, kidney, and intestine. Extracellular Ca+-levels are sensed and regulated by Calcium Sensing receptor (CASR). When Ca levels are limiting then it must be taken up by active, transcellular pathways comprising (1) Ca++ entry across apical membrane, (2) cytosolic transport of Ca++ across the cell form apical to basolateral membrane facilitated by a family of low mol wt Calcium binding proteins (CABPs) that include vitamin D3-dependent Ca++ binding proteins (calbindin-D9k, Calbindin-28k, Calretinin, Parvalbumin, S100, calmodulin) and finally (3) an active extrusion of Ca++ through basolateral membrane mediated by Ca++-ATPase and Na+-Ca++ exchangers (NCX). Ca++ absorption in intestine and its reabsorption in kidney are carried out by Ca++ Transport (CaT) proteins, CaT-1, CaT-2 or Epithelial Ca Channel (ECAC1/ECAC2/CaT-Like (CaT-L) proteins.
CAT1 (rat/mouse 727 aa; human 725 aa, chromosome 7q33-q34; ~85kD) is also known as ECAC2, CAT-like (CATL) or TRPV6 (transient receptor potential cation channel, subfamily V, member 6) contains a cytoplasmic N-terminus, 6 ankyrin repeat domains, 6 transmembrane domains, an extracellular pore region between TM5-6, and cytoplasmic C-terminus. CaT-1 shows 75% sequence identity to epithelial Ca++ channel (ECaC) protein from rabbit kidney. In rat, CaT-1 transcript (3-Kb) is expressed in duodenum, proximal jejunum cecum and colon but not in kidney; whereas ECaC in rabbit is expressed in apical cell membranes in distal part of nephron (kidney), duodenum, jejunum and placenta. The 6.5 Kb CaT-1-transcript in brain, thymus and adrenal gland and expressed sequences in rat and human brain and human prostate, spleen, placenta and lung suggest additional roles for CaT-1 beyond the intestinal Ca++ absorption.
仕様
Size：100ug
Source Antigen：Rat synthetic peptide
Grade：Highly Purified
Purity：Highly purified
Form：Supplied as a liquid in PBS, pH 7.2
Specificity：Peptide is 100% conserved in rat, mouse and 94% in Cat-1/htrp8A and htrp8b proteins. No significant sequence homology is seen with CaT-2 or other proteins
