Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
J Physiol
2018 Aug 01;59616:3637-3653. doi: 10.1113/JP276241.
Show Gene links
Show Anatomy links
Exploring the autoinhibitory domain of the electrogenic Na+ /HCO3- transporter NBCe1-B, from residues 28 to 62.
Lee SK
,
Boron WF
.
???displayArticle.abstract???
KEY POINTS: Slc4a4 (mouse) encodes at least five variants of the electrogenic sodium/bicarbonate transporter NBCe1. The initial 41 cytosolic amino acids of NBCe1-A and -D are unique; NBCe1-A has high activity. The initial 85 amino acids of NBCe1-B, -C and -E are unique; NBCe1-B and -C have low activity. Previous work showed that deleting residues 1-85 or 40-62 of NBCe1-B, or 1-87 of NBCe1-C, eliminates autoinhibition. These regions also include binding determinants for IRBIT (inositol trisphosphate (IP3 )-receptor binding protein released with IP3 ), which relieves autoinhibition. Here, systematically replacing/deleting residues 28-62, we find that only the nine amino acid cationic cluster (residues 40-48) of NBCe1-B is essential for autoinhibition. IRBIT stimulates all but one low-activity construct. We suggest that electrostatic interactions - which IRBIT presumably interrupts - between the cationic cluster and the membrane or other domains of NBCe1 play a central role in tempering the activity of NBCe1-B in the pancreas, brain and other organs.
ABSTRACT: Variant B of the electrogenic Na+ /HCO3- cotransporter (NBCe1-B) contributes to the vectorial transport of HCO3- in epithelia (e.g. pancreatic ducts) and to the maintenance of intracellular pH in the central nervous systems (e.g. astrocytes). NBCe1-B has very low basal activity due to an autoinhibitory domain (AID) located, at least in part, in the unique portion (residues 1-85) of the cytosolic NH2 -terminus. Previous work has shown that removing 23 amino acids (residues 40-62) stimulates NBCe1-B. Here, we test the hypothesis that a cationic cluster of nine consecutive positively charged amino acids (residues 40-48) is a necessary part of the AID. Using two-electrode voltage clamping of Xenopus oocytes, we assess the activity of human NBCe1-B constructs in which we systematically replace or delete residues 28-62, which includes the cationic cluster. We find that replacing or deleting all residues within the cationic cluster markedly increases NBCe1-B activity (i.e. eliminates autoinhibition). On the background of a cationic clusterless construct, systematically restoring Arg residues restores autoinhibition in two distinct quanta, with one to three Arg residues restoring ∼50%, and four or more Arg residues restoring virtually all autoinhibition. Systematically deleting residues before the cluster reduces autoinhibition by, at most, a small amount. Replacing or deleting residues after the cluster has no effect. For constructs with low NBCe1 activity (but good surface expression, as assessed by biotinylation), co-expression with super-IRBIT (lacking PP1-binding site) restores full activity (i.e. relieves autoinhibition). In summary, the cationic cluster is a necessary component of the AID of NBCe1-B.
Ando,
IRBIT, a novel inositol 1,4,5-trisphosphate (IP3) receptor-binding protein, is released from the IP3 receptor upon IP3 binding to the receptor.
2003, Pubmed
Ando,
IRBIT, a novel inositol 1,4,5-trisphosphate (IP3) receptor-binding protein, is released from the IP3 receptor upon IP3 binding to the receptor.
2003,
Pubmed
Bogdanov,
Lipids and topological rules governing membrane protein assembly.
2014,
Pubmed
Boron,
Intracellular pH regulation in the renal proximal tubule of the salamander. Basolateral HCO3- transport.
1983,
Pubmed
Burnham,
Cloning and functional expression of a human kidney Na+:HCO3- cotransporter.
1997,
Pubmed
Chambrey,
Renal intercalated cells are rather energized by a proton than a sodium pump.
2013,
Pubmed
Devogelaere,
The IRBIT domain adds new functions to the AHCY family.
2008,
Pubmed
Dutzler,
X-ray structure of a ClC chloride channel at 3.0 A reveals the molecular basis of anion selectivity.
2002,
Pubmed
Estévez,
CLC chloride channels: correlating structure with function.
2002,
Pubmed
Faraldo-Gómez,
Electrostatics of ion stabilization in a ClC chloride channel homologue from Escherichia coli.
2004,
Pubmed
Gill,
Expression and purification of the cytoplasmic N-terminal domain of the Na/HCO3 cotransporter NBCe1-A: structural insights from a generalized approach.
2006,
Pubmed
Gill,
Preliminary X-ray diffraction analysis of the cytoplasmic N-terminal domain of the Na/HCO3 cotransporter NBCe1-A.
2006,
Pubmed
Grant,
The Xenopus ORFeome: A resource that enables functional genomics.
2015,
Pubmed
,
Xenbase
Hamazaki,
A novel proteasome interacting protein recruits the deubiquitinating enzyme UCH37 to 26S proteasomes.
2006,
Pubmed
Hass,
Contemporary NMR Studies of Protein Electrostatics.
2015,
Pubmed
He,
IRBIT, inositol 1,4,5-triphosphate (IP3) receptor-binding protein released with IP3, binds Na+/H+ exchanger NHE3 and activates NHE3 activity in response to calcium.
2008,
Pubmed
Hong,
Convergence of IRBIT, phosphatidylinositol (4,5) bisphosphate, and WNK/SPAK kinases in regulation of the Na+-HCO3- cotransporters family.
2013,
Pubmed
Huynh,
CryoEM structure of the human SLC4A4 sodium-coupled acid-base transporter NBCe1.
2018,
Pubmed
Jay,
Structural aspects of the red cell anion exchange protein.
1986,
Pubmed
Jeong,
Governing effect of regulatory proteins for Cl(-)/HCO3(-) exchanger 2 activity.
2016,
Pubmed
Jo,
PBEQ-Solver for online visualization of electrostatic potential of biomolecules.
2008,
Pubmed
Juretić,
Basic charge clusters and predictions of membrane protein topology.
2002,
Pubmed
Kobayashi,
Localization and characterization of the calsequestrin-binding domain of triadin 1. Evidence for a charged beta-strand in mediating the protein-protein interaction.
2000,
Pubmed
Lee,
Relief of autoinhibition of the electrogenic Na-HCO(3) [corrected] cotransporter NBCe1-B: role of IRBIT vs.amino-terminal truncation.
2012,
Pubmed
,
Xenbase
Lee,
Negatively charged amino acids within the intraluminal loop of ryanodine receptor are involved in the interaction with triadin.
2004,
Pubmed
Lee,
Substrate specificity of the electrogenic sodium/bicarbonate cotransporter NBCe1-A (SLC4A4, variant A) from humans and rabbits.
2013,
Pubmed
,
Xenbase
Lu,
Reversible and irreversible interactions of DIDS with the human electrogenic Na/HCO3 cotransporter NBCe1-A: role of lysines in the KKMIK motif of TM5.
2007,
Pubmed
,
Xenbase
McAlear,
Electrogenic Na/HCO3 cotransporter (NBCe1) variants expressed in Xenopus oocytes: functional comparison and roles of the amino and carboxy termini.
2006,
Pubmed
,
Xenbase
Morrison,
Combinatorial alanine-scanning.
2001,
Pubmed
Motta,
SHOC2 subcellular shuttling requires the KEKE motif-rich region and N-terminal leucine-rich repeat domain and impacts on ERK signalling.
2016,
Pubmed
Musa-Aziz,
Using fluorometry and ion-sensitive microelectrodes to study the functional expression of heterologously-expressed ion channels and transporters in Xenopus oocytes.
2010,
Pubmed
,
Xenbase
Nagaraj,
Deep proteome and transcriptome mapping of a human cancer cell line.
2011,
Pubmed
Obosi,
Mutational analysis of the mouse 5-HT7 receptor: importance of the third intracellular loop for receptor-G-protein interaction.
1997,
Pubmed
Park,
Irbit mediates synergy between ca(2+) and cAMP signaling pathways during epithelial transport in mice.
2013,
Pubmed
Parker,
Characterization of human SLC4A10 as an electroneutral Na/HCO3 cotransporter (NBCn2) with Cl- self-exchange activity.
2008,
Pubmed
,
Xenbase
Parker,
The divergence, actions, roles, and relatives of sodium-coupled bicarbonate transporters.
2013,
Pubmed
Pearlman,
A mechanism for the evolution of phosphorylation sites.
2011,
Pubmed
Peña-Münzenmayer,
Ae4 (Slc4a9) Anion Exchanger Drives Cl- Uptake-dependent Fluid Secretion by Mouse Submandibular Gland Acinar Cells.
2015,
Pubmed
Realini,
KEKE motifs. Proposed roles in protein-protein association and presentation of peptides by MHC class I receptors.
1994,
Pubmed
Romero,
Cloning and functional expression of rNBC, an electrogenic Na(+)-HCO3- cotransporter from rat kidney.
1998,
Pubmed
,
Xenbase
Romero,
Expression cloning and characterization of a renal electrogenic Na+/HCO3- cotransporter.
1997,
Pubmed
,
Xenbase
Romero,
The SLC4 family of bicarbonate (HCO₃⁻) transporters.
2013,
Pubmed
Roy,
I-TASSER: a unified platform for automated protein structure and function prediction.
2010,
Pubmed
Shcheynikov,
Intracellular Cl- as a signaling ion that potently regulates Na+/HCO3- transporters.
2015,
Pubmed
Shirakabe,
IRBIT, an inositol 1,4,5-trisphosphate receptor-binding protein, specifically binds to and activates pancreas-type Na+/HCO3- cotransporter 1 (pNBC1).
2006,
Pubmed
,
Xenbase
Sievers,
Fast, scalable generation of high-quality protein multiple sequence alignments using Clustal Omega.
2011,
Pubmed
Wang,
A conserved arginine in the distal third intracellular loop of the mu-opioid receptor is required for G protein activation.
1999,
Pubmed
Wang,
Basic amino acids at the C-terminus of the third intracellular loop are required for the activation of phospholipase C by cholecystokinin-B receptors.
1997,
Pubmed
,
Xenbase
Yang,
IRBIT coordinates epithelial fluid and HCO3- secretion by stimulating the transporters pNBC1 and CFTR in the murine pancreatic duct.
2009,
Pubmed
Yang,
IRBIT governs epithelial secretion in mice by antagonizing the WNK/SPAK kinase pathway.
2011,
Pubmed
van Klompenburg,
Anionic phospholipids are determinants of membrane protein topology.
1997,
Pubmed
