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.
CaT2 (rat 723 aa; human 729 aa, chromosome 7q35) is also known as ECAC1 or TRPV5) is ~75% homologous with CAT1.
In contrast to CaT-1, CaT-2 is exclusively expressed in kidney and absent in intestine, brain, heart, liver, lung, skeletal muscle, spleen, thymus, testis, adrenal gland.
It colocalizes with calbindin D28K and Na+ channel exchanger 1 (NCX1).
CaT-2 mediates saturable apical Ca++ uptake by the cells of distal convoluted tubule and connecting segment of nephron where active re-absorption of Ca++ takes place via transcellular route.
CaT-2 has moderate abilities to transport Sr++ and Ba++.
A strong inhibition of CaT-2 mediated Ca++ transport by Cd++ leads to hypercalciurea and renal stone formation
Applications:Suitable for use in ELISA.
Western Blot, though not tested, may potentially be used as an application.
ELISA: 1:10,000-1:100,000 using 50-100ng of control peptide/well (Cat # C0122)
Optimal dilutions to be determined by the researcher
Storage and Stability:May be stored at 4°C for short-term only.
For long-term storage, aliquot and store at -20°C.
Aliquots are stable for at least 12 months at -20°C.
For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
Further dilutions can be made in assay buffer.
仕様
Size:100ul
Host:rabbit
Source Antibody:rat
Grade:Serum
Purity:Serum
Form:Supplied as a liquid, 0.05% sodium azide, 40% glycerol.
Specificity:Recognizes rat Calcium Transport Protein 2. Species sequence homology: rabbit, 90%; human, 80%; mouse, 85%. No significant sequence homology is seen with CaT-1 or other proteins.
Isotype:IgG
Calc Applications Abbrev:E
Calc Crossreactivity:Rt
Immunogen:A 20-aa peptide sequence, near the cytoplasmic C-terminus of rat CaT-2/ECAC1 (KLH).