SLCO1B3-SLCO1B7 readthrough transcript protein; liver specific transporter-3 transmembrane 12; LST-3TM12; organic anion transporting polypeptide 1B3-1B7; OATP1B3-1B7; solute carrier organic anion transporter family member 1B3-1B7; SLCO1B3-SLCO1B7 (SLCO1B3-SLCO1B7)

Function: - mediates Na⁺-independent uptake of organic anions - transports the conjugated steroids 17-beta-glucuronosyl estradiol (17-beta-estradiol, 17-O-(beta-D-glucuronate or E2G) & DHEA-3-sulfate (DHEAS) at the smooth endoplasmic reticulum membrane (SER), granting access to metabolizing enzymes - contributes to the metabolism of bile acids such as taurocholate (cholyltaurine) & lithocholate, by functioning as a doorway between SER & cytosol, thus decreasing their circulating levels & protecting the organism from their detergent properties - regulates access or exit of drugs to the SER lumen - transport activity is induced by farnesoid X receptor (FXR) agonists such as chenodeoxycholate - Kinetic parameters: - KM=32.8 uM for 17beta-estradiol 17-O-(beta-D-glucuronate) - KM=34.2 uM for dehydroepiandrosterone sulfate - KM=20.4 uM for dehydroepiandrosterone sulfate - KM=15.99 uM for taurocholate - Vmax=29.7 pmol/min/mg protein with 17beta-estradiol 17-O-(beta-D-glucuronate) - Vmax=300.2 pmol/min/mg protein with dehydroepiandrosterone sulfate - Vmax=264.3 pmol/min/mg protein with dehydroepiandrosterone sulfate - Vmax=17.38 pmol/min/mg protein with taurocholate 17-beta-estradiol 17-O-(beta-D-glucuronate)(out) = 17-beta-estradiol 17-O-(beta-D-glucuronate)(in) DHEA-3-sulfate(out) = DHEA-3-sulfate(in) taurocholate(out) = taurocholate(in) lithocholate(out) = lithocholate(in) Structure: - belongs to the organo anion transporter (TC 2.A.60) family Compartment: - smooth endoplasmic reticulum membrane, multi-pass membrane protein - cell membrane, multi-pass membrane protein - endoplasmic reticulum membrane, multi-pass membrane protein Alternative splicing: - named isoforms=4: SLCO1B3-SLCO1B7-1, SLCO1B3-1, SLCO1B3-2, SLCO1B7-1 Expression: - expressed in the perivenular areas (centrilobular) of the liver (at protein level) Notes: - based on a naturally occurring readthrough transcript which produces an SLCO1B3-SLCO1B7 fusion protein where the first 5 exons originate from SLCO1B3, while SLCO1B7 provides the remaining exons - the resulting mRNA encodes for a functional transporter SLCO1B3-SLCO1B7

General

carrier protein (transporter) glycoprotein transmembrane 12 protein

Properties

SIZE: entity length = 687 aa MW = 76 kD COMPARTMENT: endoplasmic reticulum MOTIF: transmembrane domain {30-50} transmembrane domain {64-84} transmembrane domain {97-117} N-glycosylation site {N134} N-glycosylation site {N151} transmembrane domain {171-191} transmembrane domain {207-227} transmembrane domain {259-279} transmembrane domain {340-360} transmembrane domain {377-397} transmembrane domain {410-430} cysteine residue {C459} MODIFICATION: cysteine residue {C489} cysteine residue {C465} MODIFICATION: cysteine residue {C485} cysteine residue {C474} MODIFICATION: cysteine residue {C506} cysteine residue {C485} MODIFICATION: cysteine residue {C465} cysteine residue {C489} MODIFICATION: cysteine residue {C459} N-glycosylation site {N503} cysteine residue {C506} MODIFICATION: cysteine residue {C474} N-glycosylation site {N516} transmembrane domain {540-560} transmembrane domain {569-589} N-glycosylation site {N617} transmembrane domain {625-645}

Database Correlations

UniProt F5H094 PFAM correlations

References

UniProt :accession F5H094 - UniProt PubMed refs - PMID: 29248594 - PMID: 31127008 - PMID: 127008 - PMID: 32818652 - PMID: 31509437 - PMID: 509437