1
|
Sohail I, Hassan MU, Schmid D, Chiba P. The noncanonical nucleotide binding site 1 of the bile salt export pump is optimized for proper function of the transporter. Cell Biol Int 2024; 48:638-646. [PMID: 38328902 DOI: 10.1002/cbin.12136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 12/19/2023] [Accepted: 01/28/2024] [Indexed: 02/09/2024]
Abstract
The bile salt export pump (ABCB11/BSEP) is a hepatocyte plasma membrane-resident protein translocating bile salts into bile canaliculi. The sequence alignment of the four full-length transporters of the ABCB subfamily (ABCB1, ABCB4, ABCB5 and ABCB11) indicates that the NBD-NBD contact interface of ABCB11 differs from that of other members in only four residues. Notably, these are all located in the noncanonical nucleotide binding site 1 (NBS1). Substitution of all four deviant residues with canonical ones (quadruple mutant) significantly decreased the transport activity of the protein. In this study, we mutated two deviant residues in the signature sequence to generate a double mutant (R1221G/E1223Q). Furthermore, a triple mutant (E502S/R1221G/E1223Q) was generated, in which the deviant residues of the signature sequence and Q-loop were mutated concurrently to canonical residues. The double and triple mutants showed 80% and 60%, respectively, of the activity of wild-type BSEP. As expected, an increasing number of mutations gradually impair transport as an intricate network of interactions within the ABC proteins ensures proper functioning.
Collapse
Affiliation(s)
- Imran Sohail
- Department of Zoology, Government College University Lahore, Lahore, Pakistan
- Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
| | - Mahmood Ul Hassan
- Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
- Institute of Industrial Biotechnology, Government College University Lahore, Lahore, Pakistan
| | - Diethart Schmid
- Institute of Physiology, Medical University of Vienna, Vienna, Austria
| | - Peter Chiba
- Institute of Medical Chemistry, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
3
|
Marinko J, Huang H, Penn WD, Capra JA, Schlebach JP, Sanders CR. Folding and Misfolding of Human Membrane Proteins in Health and Disease: From Single Molecules to Cellular Proteostasis. Chem Rev 2019; 119:5537-5606. [PMID: 30608666 PMCID: PMC6506414 DOI: 10.1021/acs.chemrev.8b00532] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Indexed: 12/13/2022]
Abstract
Advances over the past 25 years have revealed much about how the structural properties of membranes and associated proteins are linked to the thermodynamics and kinetics of membrane protein (MP) folding. At the same time biochemical progress has outlined how cellular proteostasis networks mediate MP folding and manage misfolding in the cell. When combined with results from genomic sequencing, these studies have established paradigms for how MP folding and misfolding are linked to the molecular etiologies of a variety of diseases. This emerging framework has paved the way for the development of a new class of small molecule "pharmacological chaperones" that bind to and stabilize misfolded MP variants, some of which are now in clinical use. In this review, we comprehensively outline current perspectives on the folding and misfolding of integral MPs as well as the mechanisms of cellular MP quality control. Based on these perspectives, we highlight new opportunities for innovations that bridge our molecular understanding of the energetics of MP folding with the nuanced complexity of biological systems. Given the many linkages between MP misfolding and human disease, we also examine some of the exciting opportunities to leverage these advances to address emerging challenges in the development of therapeutics and precision medicine.
Collapse
Affiliation(s)
- Justin
T. Marinko
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Hui Huang
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
| | - Wesley D. Penn
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - John A. Capra
- Center
for Structural Biology, Vanderbilt University, Nashville, Tennessee 37240, United States
- Department
of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37245, United States
| | - Jonathan P. Schlebach
- Department
of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Charles R. Sanders
- Department
of Biochemistry, Vanderbilt University, Nashville, Tennessee 37240, United States
| |
Collapse
|
4
|
Nataraja S, Sriraman V, Palmer S. Allosteric Regulation of the Follicle-Stimulating Hormone Receptor. Endocrinology 2018; 159:2704-2716. [PMID: 29800292 DOI: 10.1210/en.2018-00317] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Accepted: 05/16/2018] [Indexed: 01/08/2023]
Abstract
Follicle-stimulating hormone receptor (FSHR) belongs to the leucine-rich repeat family of the G protein-coupled receptor (LGR), which includes the glycoprotein hormone receptors luteinizing hormone receptor, thyrotropin receptor, and other LGRs 4, 5, 6, and 7. FSH is the key regulator of folliculogenesis in females and spermatogenesis in males. FSH elicits its physiological response through its cognate receptor on the cell surface. Binding of the hormone FSH to its receptor FSHR brings about conformational changes in the receptor that are transduced through the transmembrane domain to the intracellular region, where the downstream effector interaction takes place, leading to activation of the downstream signaling cascade. Identification of small molecules that could activate or antagonize FSHR provided interesting tools to study the signal transduction mechanism of the receptor. However, because of the nature of the ligand-receptor interaction of FSH-FSHR, which contains multiple sites in the extracellular binding domain, most of the small-molecule modulators of FSHR are unable to bind to the orthosteric site of the receptors. Rather they modulate receptor activation through allosteric sites in the transmembrane region. This review will discuss allosteric modulation of FSHR primarily through the discovery of small-molecule modulators, focusing on current data on the status of development and the utility of these as tools to better understand signaling mechanisms.
Collapse
|
5
|
Sohail MI, Schmid D, Wlcek K, Spork M, Szakács G, Trauner M, Stockner T, Chiba P. Molecular Mechanism of Taurocholate Transport by the Bile Salt Export Pump, an ABC Transporter Associated with Intrahepatic Cholestasis. Mol Pharmacol 2017; 92:401-413. [PMID: 28784620 DOI: 10.1124/mol.117.108688] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 07/31/2017] [Indexed: 12/12/2022] Open
Abstract
The bile salt export pump (BSEP/ABCB11) transports bile salts from hepatocytes into bile canaliculi. Its malfunction is associated with severe liver disease. One reason for functional impairment of BSEP is systemic administration of drugs, which as a side effect inhibit the transporter. Therefore, drug candidates are routinely screened for potential interaction with this transporter. Hence, understanding the functional biology of BSEP is of key importance. In this study, we engineered the transporter to dissect interdomain communication paths. We introduced mutations in noncanonical and in conserved residues of either of the two nucleotide binding domains and determined the effect on BSEP basal and substrate-stimulated ATPase activity as well as on taurocholate transport. Replacement of the noncanonical methionine residue M584 (Walker B sequence of nucleotide binding site 1) by glutamate imparted hydrolysis competency to this site. Importantly, this mutation was able to sustain 15% of wild-type transport activity, when the catalytic glutamate of the canonical nucleotide binding site 2 was mutated to glutamine. Kinetic modeling of experimental results for the ensuing M584E/E1244Q mutant suggests that a transfer of hydrolytic capacity from the canonical to the noncanonical nucleotide binding site results in loss of active and adoption of facilitative characteristics. This facilitative transport is ATP-gated. To the best of our knowledge, this result is unprecedented in ATP-binding cassette proteins with one noncanonical nucleotide binding site. Our study promotes an understanding of the domain interplay in BSEP as a basis for exploration of drug interactions with this transporter.
Collapse
Affiliation(s)
- Muhammad Imran Sohail
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| | - Diethart Schmid
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| | - Katrin Wlcek
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| | - Matthias Spork
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| | - Gergely Szakács
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| | - Michael Trauner
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| | - Thomas Stockner
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| | - Peter Chiba
- Institute of Medical Chemistry, Center for Pathobiochemistry and Genetics (M.I.S., M.S., P.C.), Institute of Physiology, Center for Physiology and Pharmacology (D.S.), Institute of Cancer Research (G.S.), Hans Popper Laboratory of Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine III (M.T.), and Institute of Pharmacology, Center for Physiology and Pharmacology (T.S.), Medical University of Vienna, Vienna, Austria; Department of Zoology, Government College University Lahore, Lahore, Pakistan (M.I.S.); and Department of Pharmaceutical Chemistry, Faculty of Life Sciences, University of Vienna, Vienna, Austria (K.W.)
| |
Collapse
|