Solute carrier organic anion transporter family member 2B1

Solute carrier organic anion transporter family member 2B1

Mediates the Na(+)-independent transport of steroid sulfate conjugates and other specific organic anions10873595,11159893,11932330,12724351,14610227,16908597,18501590,20507927,22201122,23531488,25132355,26383540,27576593,28408210,29871943,34628357. Responsible for the transport of estrone 3-sulfate (E1S) through the basal membrane of syncytiotrophoblast, highlighting a potential role in the placental absorption of fetal-derived sulfated steroids including the steroid hormone precursor dehydroepiandrosterone sulfate (DHEA-S)11932330,12409283. Also facilitates the uptake of sulfated steroids at the basal/sinusoidal membrane of hepatocytes, therefore accounting for the major part of organic anions clearance of liver11159893. Mediates the intestinal uptake of sulfated steroids12724351,28408210. Mediates the uptake of the neurosteroids DHEA-S and pregnenolone sulfate (PregS) into the endothelial cells of the blood-brain barrier as the first step to enter the brain16908597,25132355. Also plays a role in the reuptake of neuropeptides such as substance P/TAC1 and vasoactive intestinal peptide/VIP released from retinal neurons25132355. May act as a heme transporter that promotes cellular iron availability via heme oxygenase/HMOX2 and independently of TFRC35714613. Also transports heme by-product coproporphyrin III (CPIII), and may be involved in their hepatic disposition26383540. Mediates the uptake of other substrates such as prostaglandins D2 (PGD2), E1 (PGE1) and E2 (PGE2), taurocholate, L-thyroxine, leukotriene C4 and thromboxane B210873595,14610227,19129463,29871943,Ref.25. May contribute to regulate the transport of organic compounds in testis across the blood-testis-barrier (Probable). Shows a pH-sensitive substrate specificity which may be ascribed to the protonation state of the binding site and leads to a stimulation of substrate transport in an acidic microenvironment14610227,19129463,22201122. The exact transport mechanism has not been yet deciphered but most likely involves an anion exchange, coupling the cellular uptake of organic substrate with the efflux of an anionic compound19129463,20507927,26277985. Hydrogencarbonate/HCO3(-) acts as a probable counteranion that exchanges for organic anions19129463. Cytoplasmic glutamate may also act as counteranion in the placenta26277985. An inwardly directed proton gradient has also been proposed as the driving force of E1S uptake with a (H(+):E1S) stoichiometry of (1:1)20507927

Has estrone 3-sulfate (E1S) transport activity comparable with the full-length isoform 1

Quoted from UniProt’s FUNCTION annotation for O94956 (reviewed). The superscript numbers are UniProt’s own PubMed citations, kept in the sentence and in order, each linking to the paper it names.

What it acts with

STRING’s highest-confidence human functional partners. The combined score mixes several kinds of evidence, so each channel is shown separately — a partner supported by experiment is a different claim from one supported only by text mining, and for a receptor this is where its coupling appears as evidence rather than as assertion.

Where it sits in the cell

UniProt, curated Cell membrane · Basal cell membrane · Basolateral cell membrane · Apical cell membrane

Expression by cell type

Single cell type RNA, the 6 highest of those the Human Protein Atlas reports for this gene. Transcript, not protein, and a cell type rather than a tissue.

• Microglia659 nCPM
• Mast cells527.7 nCPM
• Kupffer cells467.4 nCPM
• Macrophages421.7 nCPM
• Hepatocytes263.8 nCPM
• Hofbauer cells262.9 nCPM

Expression by tissue

The tissues this gene is enriched in, by consensus RNA. A tissue absent from this list is one the Atlas does not call specific for this gene, which is not the same as absent from it.

• liver214.5 nTPM