A conserved GXXXG motif in the transmembrane domain of CLIC proteins is essential for their cholesterol-dependant membrane interaction. 2019

Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
School of Life Sciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia.

Sterols have been reported to modulate conformation and hence the function of several membrane proteins. One such group is the Chloride Intracellular Ion Channel (CLIC) family of proteins. The CLIC protein family consists of six evolutionarily conserved protein members in vertebrates. These proteins exist as both monomeric soluble proteins and as membrane bound proteins. To date, the structure of their membrane-bound form remains unknown. In addition to several studies indicating cellular redox environment and pH as facilitators of CLIC1 insertion into membranes, we have also demonstrated that the spontaneous membrane insertion of CLIC1 is regulated by membrane cholesterol. We have performed Langmuir-film, Impedance Spectroscopy and Molecular Docking Simulations to study the role of this GXXXG motif in CLIC1 interaction with cholesterol. Unlike CLIC1-wild-type protein, the G18A and G22A mutants, that form part of the GXXXG motif, showed much slower initial kinetics and lower ion channel activity compared to the native protein. This difference can be attributed to the significantly reduced membrane interaction and insertion rate of the mutant proteins and/or slower formation of the final membrane configuration of the mutant proteins once in the membrane. In this study, our findings uncover the identification of a GXXXG motif in CLIC1, which likely serves as the cholesterol-binding domain, that facilitates the protein's membrane interaction and insertion. Furthermore, we were able to postulate a model by which CLIC1 can autonomously insert into membranes to form functional ion channels. Members of the CLIC family of proteins demonstrate unusual structural and dual functional properties - as ion channels and enzymes. Elucidating how the CLIC proteins' interact with membranes, thus allowing them to switch between their soluble and membrane form, will provide key information as to a mechanism of moonlighting activity and a novel regulatory role for cholesterol in such a process.

UI MeSH Term Description Entries
D011485 Protein Binding The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments. Plasma Protein Binding Capacity,Binding, Protein
D002462 Cell Membrane The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells. Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D002784 Cholesterol The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils. Epicholesterol
D005998 Glycine A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter. Aminoacetic Acid,Glycine, Monopotassium Salt,Glycine Carbonate (1:1), Monosodium Salt,Glycine Carbonate (2:1), Monolithium Salt,Glycine Carbonate (2:1), Monopotassium Salt,Glycine Carbonate (2:1), Monosodium Salt,Glycine Hydrochloride,Glycine Hydrochloride (2:1),Glycine Phosphate,Glycine Phosphate (1:1),Glycine Sulfate (3:1),Glycine, Calcium Salt,Glycine, Calcium Salt (2:1),Glycine, Cobalt Salt,Glycine, Copper Salt,Glycine, Monoammonium Salt,Glycine, Monosodium Salt,Glycine, Sodium Hydrogen Carbonate,Acid, Aminoacetic,Calcium Salt Glycine,Cobalt Salt Glycine,Copper Salt Glycine,Hydrochloride, Glycine,Monoammonium Salt Glycine,Monopotassium Salt Glycine,Monosodium Salt Glycine,Phosphate, Glycine,Salt Glycine, Monoammonium,Salt Glycine, Monopotassium,Salt Glycine, Monosodium
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000595 Amino Acid Sequence The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION. Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D017124 Conserved Sequence A sequence of amino acids in a polypeptide or of nucleotides in DNA or RNA that is similar across multiple species. A known set of conserved sequences is represented by a CONSENSUS SEQUENCE. AMINO ACID MOTIFS are often composed of conserved sequences. Conserved Sequences,Sequence, Conserved,Sequences, Conserved
D017433 Protein Structure, Secondary The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to ALPHA-HELICES; BETA-STRANDS (which align to form BETA-SHEETS), or other types of coils. This is the first folding level of protein conformation. Secondary Protein Structure,Protein Structures, Secondary,Secondary Protein Structures,Structure, Secondary Protein,Structures, Secondary Protein
D058266 Dielectric Spectroscopy A technique of measuring the dielectric properties of materials, which vary over a range of frequencies depending on the physical properties of the material. The technique involves measuring, over a range of frequencies, ELECTRICAL IMPEDANCE and phase shift of an electric field as it passes through the material. Electrochemical Impedance Spectroscopy,Impedance Spectroscopy,Electrochemical Impedance Spectroscopies,Impedance Spectroscopies,Impedance Spectroscopies, Electrochemical,Impedance Spectroscopy, Electrochemical,Spectroscopies, Electrochemical Impedance,Spectroscopies, Impedance,Spectroscopy, Dielectric,Spectroscopy, Electrochemical Impedance,Spectroscopy, Impedance
D018118 Chloride Channels Cell membrane glycoproteins that form channels to selectively pass chloride ions. Nonselective blockers include FENAMATES; ETHACRYNIC ACID; and TAMOXIFEN. CaCC,Calcium-Activated Chloride Channel,Chloride Ion Channel,Chlorine Channel,Ion Channels, Chloride,CaCCs,Calcium-Activated Chloride Channels,Chloride Channel,Chloride Ion Channels,Chlorine Channels,Ion Channel, Chloride,Calcium Activated Chloride Channel,Calcium Activated Chloride Channels,Channel, Calcium-Activated Chloride,Channel, Chloride,Channel, Chloride Ion,Channel, Chlorine,Channels, Calcium-Activated Chloride,Channels, Chloride,Channels, Chloride Ion,Channels, Chlorine,Chloride Channel, Calcium-Activated,Chloride Channels, Calcium-Activated

Related Publications

Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
February 2000, Journal of molecular biology,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
January 2013, Journal of virology,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
January 2016, Molecular plant pathology,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
September 2006, Biochemistry,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
April 2003, European journal of biochemistry,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
April 2003, The Journal of biological chemistry,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
April 2014, The Journal of biological chemistry,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
August 2015, Biochemistry,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
July 1994, Genes & development,
Khondker Rufaka Hossain, and Daniel R Turkewitz, and Stephen A Holt, and Leonie Herson, and Louise J Brown, and Bruce A Cornell, and Paul M G Curmi, and Stella M Valenzuela
August 2007, Journal of virology,
Copied contents to your clipboard!