Mammalian kidney and liver are critical in maintaining physiological ionic environment. Kidney specializes in removing toxins, drugs, and other organic anions from the blood by a process called “renal secretion”. Besides kidney, anionic substrates are also transported in other organs, e.g., choroid plexus, eye, airway, and placenta. Several multispecific OATs (OAT1-3, OAT-K1 and OATK2) and OATPs (organic anion transporting polypeptides; oatp1-3), have been cloned and characterized from various tissues. OATPs family of proteins are very similar in sequence and secondary protein structure (up to 12 transmembrane domains with cytoplasmic N and C-terminus).
A kidney-specific anion transporter termed OAT-K1 (rat 669 aa) has been cloned from rat kidney. OAT-K1 mRNA is specifically expressed in brush-borer membrane of the proximal straight tubules. Rat OAT-K1 (669 aa) shows 72% identity with rat liver oatp. It mediates basolateral uptake of anionic methotrexate but not PAH, taurocholate, and prostaglandin E2. OAT-K2 (498 aa), very similar to OAT-K1 (91% identity), has also been cloned from rat kidney. It also has 62-65% homology with oatp1-3 family of proteins. OAT-K2 is predominantly expressed in convoluted tubules, proximal straight tubules, and cortical collecting ducts. OAT-K2 mediates uptake of hydrophobic anions such as taurocholate, methotrexate, folate, and prostaglandin E2 suggesting that OAT-K2 participate in epithelial transport of hydrophobic anionic compound in the kidney.
Sequence: 10 aa peptide sequence near the cytoplasmic, C-terminus of rat OAT-K2
Specificity: The 10aa rat control peptide is 100% conserved in both rat OAT-K1 (669 aa), and OAT-K2 (498 aa). Therefore, this antibody will detect both OAT-K1 and K2. No significant sequence homology is detected with other OATs. Antibody crossreactivity in various species has not been studied. The control peptide is available to confirm specificity of antibodies.
Form: Supplied as a liquid in PBS, pH 7.2, 0.1% sodium azide.
Applications:Suitable for use in ELISA and Antibody Blocking.
Storage and Stability:May be stored at 4°C for short-term only. For long-term storage, store at -20°C. Aliquots are stable for at least 6 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.
