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Silnitsky S, Rubin SJS, Zerihun M, Qvit N. An Update on Protein Kinases as Therapeutic Targets-Part I: Protein Kinase C Activation and Its Role in Cancer and Cardiovascular Diseases. Int J Mol Sci 2023; 24:17600. [PMID: 38139428 PMCID: PMC10743896 DOI: 10.3390/ijms242417600] [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: 11/01/2023] [Revised: 12/10/2023] [Accepted: 12/12/2023] [Indexed: 12/24/2023] Open
Abstract
Protein kinases are one of the most significant drug targets in the human proteome, historically harnessed for the treatment of cancer, cardiovascular disease, and a growing number of other conditions, including autoimmune and inflammatory processes. Since the approval of the first kinase inhibitors in the late 1990s and early 2000s, the field has grown exponentially, comprising 98 approved therapeutics to date, 37 of which were approved between 2016 and 2021. While many of these small-molecule protein kinase inhibitors that interact orthosterically with the protein kinase ATP binding pocket have been massively successful for oncological indications, their poor selectively for protein kinase isozymes have limited them due to toxicities in their application to other disease spaces. Thus, recent attention has turned to the use of alternative allosteric binding mechanisms and improved drug platforms such as modified peptides to design protein kinase modulators with enhanced selectivity and other pharmacological properties. Herein we review the role of different protein kinase C (PKC) isoforms in cancer and cardiovascular disease, with particular attention to PKC-family inhibitors. We discuss translational examples and carefully consider the advantages and limitations of each compound (Part I). We also discuss the recent advances in the field of protein kinase modulators, leverage molecular docking to model inhibitor-kinase interactions, and propose mechanisms of action that will aid in the design of next-generation protein kinase modulators (Part II).
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Affiliation(s)
- Shmuel Silnitsky
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Henrietta Szold St. 8, Safed 1311502, Israel; (S.S.); (M.Z.)
| | - Samuel J. S. Rubin
- Department of Medicine, School of Medicine, Stanford University, 300 Pasteur Drive, Stanford, CA 94305, USA;
| | - Mulate Zerihun
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Henrietta Szold St. 8, Safed 1311502, Israel; (S.S.); (M.Z.)
| | - Nir Qvit
- The Azrieli Faculty of Medicine in the Galilee, Bar-Ilan University, Henrietta Szold St. 8, Safed 1311502, Israel; (S.S.); (M.Z.)
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Shu Y, Gumma N, Hassan F, Branch DA, Baer LA, Ostrowski MC, Stanford KI, Baskin KK, Mehta KD. Hepatic protein kinase Cbeta deficiency mitigates late-onset obesity. J Biol Chem 2023; 299:104917. [PMID: 37315788 PMCID: PMC10393818 DOI: 10.1016/j.jbc.2023.104917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/27/2023] [Accepted: 05/30/2023] [Indexed: 06/16/2023] Open
Abstract
Although aging is associated with progressive adiposity and a decline in liver function, the underlying molecular mechanisms and metabolic interplay are incompletely understood. Here, we demonstrate that aging induces hepatic protein kinase Cbeta (PKCβ) expression, while hepatocyte PKCβ deficiency (PKCβHep-/-) in mice significantly attenuates obesity in aged mice fed a high-fat diet. Compared with control PKCβfl/fl mice, PKCβHep-/- mice showed elevated energy expenditure with augmentation of oxygen consumption and carbon dioxide production which was dependent on β3-adrenergic receptor signaling, thereby favoring negative energy balance. This effect was accompanied by induction of thermogenic genes in brown adipose tissue (BAT) and increased BAT respiratory capacity, as well as a shift to oxidative muscle fiber type with an improved mitochondrial function, thereby enhancing oxidative capacity of thermogenic tissues. Furthermore, in PKCβHep-/- mice, we determined that PKCβ overexpression in the liver mitigated elevated expression of thermogenic genes in BAT. In conclusion, our study thus establishes hepatocyte PKCβ induction as a critical component of pathophysiological energy metabolism by promoting progressive hepatic and extrahepatic metabolic derangements in energy homeostasis, contributing to late-onset obesity. These findings have potential implications for augmenting thermogenesis as a means of combating aging-induced obesity.
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Affiliation(s)
- Yaoling Shu
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Nikhil Gumma
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Faizule Hassan
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Daniel A Branch
- Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Lisa A Baer
- Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Michael C Ostrowski
- Department of Biochemistry & Molecular Biology, Holling Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Kristin I Stanford
- Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Kedryn K Baskin
- Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Kamal D Mehta
- Department of Biological Chemistry & Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA; Division of Metabolic Syndrome, Instacare Therapeutics, Dublin, Ohio, USA.
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Insertion Depth Modulates Protein Kinase C-δ-C1b Domain Interactions with Membrane Cholesterol as Revealed by MD Simulations. Int J Mol Sci 2023; 24:ijms24054598. [PMID: 36902029 PMCID: PMC10002858 DOI: 10.3390/ijms24054598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023] Open
Abstract
Protein kinase C delta (PKC-δ) is an important signaling molecule in human cells that has both proapoptotic as well as antiapoptotic functions. These conflicting activities can be modulated by two classes of ligands, phorbol esters and bryostatins. Phorbol esters are known tumor promoters, while bryostatins have anti-cancer properties. This is despite both ligands binding to the C1b domain of PKC-δ (δC1b) with a similar affinity. The molecular mechanism behind this discrepancy in cellular effects remains unknown. Here, we have used molecular dynamics simulations to investigate the structure and intermolecular interactions of these ligands bound to δC1b with heterogeneous membranes. We observed clear interactions between the δC1b-phorbol complex and membrane cholesterol, primarily through the backbone amide of L250 and through the K256 side-chain amine. In contrast, the δC1b-bryostatin complex did not exhibit interactions with cholesterol. Topological maps of the membrane insertion depth of the δC1b-ligand complexes suggest that insertion depth can modulate δC1b interactions with cholesterol. The lack of cholesterol interactions suggests that bryostatin-bound δC1b may not readily translocate to cholesterol-rich domains within the plasma membrane, which could significantly alter the substrate specificity of PKC-δ compared to δC1b-phorbol complexes.
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Heinonen S, Lautala S, Koivuniemi A, Bunker A. Insights into the behavior of unsaturated diacylglycerols in mixed lipid bilayers in relation to protein kinase C activation-A molecular dynamics simulation study. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183961. [PMID: 35568204 DOI: 10.1016/j.bbamem.2022.183961] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
The lipid second messenger diacylglycerol (DAG) is known for its involvement in many types of cellular signaling, especially as an endogenous agonist for protein kinase C (PKC). Evidence has emerged that the degree of saturation of the DAG molecules can affect PKC activation. DAG molecules with different acyl chain saturation have not only been observed to induce varying extents of PKC activation, but also to express selectivity towards different PKC isozymes. Both qualities are important for precise therapeutic activation of PKC; understanding DAG behavior at the molecular level in different environments has much potential in the development of drugs to target PKC. We used molecular dynamics simulations to study the behavior of two different unsaturated DAG species in lipid environments with varying degrees of unsaturation. We focus on phosphatidylethanolamine (PE) instead of phosphatidylcholine (PC) to more accurately model the relevant biomembranes. The effect of cholesterol (CHOL) on these systems was also explored. We found that both high level of unsaturation in the acyl chains of the DAG species and presence of CHOL in the surrounding membrane increase DAG molecule availability at the lipid-water interface. This can partially explain the previously observed differences in PKC activation strength and specificity, the complete mechanism is, however, likely to be more complex. Our simulations coupled with the current understanding of lipids highlight the need for more simulations of biologically accurate lipid environments in order to determine the correct correlations between molecular mechanisms and biological behavior when studying PKC activation.
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Affiliation(s)
- Suvi Heinonen
- Drug Research Program, Division of Pharmaceutical Biosciences, University of Helsinki, FI-00014, Helsinki, Finland
| | - Saara Lautala
- Drug Research Program, Division of Pharmaceutical Biosciences, University of Helsinki, FI-00014, Helsinki, Finland.
| | - Artturi Koivuniemi
- Drug Research Program, Division of Pharmaceutical Biosciences, University of Helsinki, FI-00014, Helsinki, Finland
| | - Alex Bunker
- Drug Research Program, Division of Pharmaceutical Biosciences, University of Helsinki, FI-00014, Helsinki, Finland
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5
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Bukiya AN, Dopico AM. Cholesterol antagonism of alcohol inhibition of smooth muscle BK channel requires cell integrity and involves a protein kinase C-dependent mechanism(s). Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1866:158874. [PMID: 33383194 DOI: 10.1016/j.bbalip.2020.158874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 12/13/2020] [Accepted: 12/22/2020] [Indexed: 10/22/2022]
Abstract
Alcohol constricts cerebral arteries via inhibition of voltage/calcium-gated, large conductance potassium (BK) channels in vascular myocytes. Using a rat model of high-cholesterol (high-CLR) diet and CLR enrichment of cerebral arteries in vitro, we recently showed that CLR protected against alcohol-induced constriction of cerebral arteries. The subcellular mechanism(s) underlying CLR protection against alcohol-induced constriction of the artery is unclear. Here we use a rat model of high-CLR diet and patch-clamp recording of BK channels in inside-out patches from cerebral artery myocytes to demonstrate that this diet antagonizes inhibition of BK currents by 50 mM ethanol. High-CLR-driven protection against alcohol inhibition of BK currents is reversed following CLR depletion in vitro. Similar to CLR accumulation in vivo, pre-incubation of arterial myocytes from normocholesterolemic rats in CLR-enriching media in vitro protects against alcohol-induced inhibition of BK current. However, application of CLR-enriching media to cell-free membrane patches does not protect against the alcohol effect. These different outcomes point to the involvement of cell signaling in CLR-alcohol interaction on BK channels. Incubation of myocytes with the PKC activators phorbol 12-myristate 13-acetate or 1,2-dioctanoyl-sn-glycerol, but not with the PKC inhibitor Gouml 6983, prior to patch excision precludes CLR enrichment from antagonizing alcohol action. Thus, PKC activation either disables the CLR target(s) or competes with elevated CLR. Favoring the latter possibility, 1,2-dioctanoyl-sn-glycerol protects against alcohol-induced inhibition of BK currents in patches from myocytes with naïve CLR. Our findings document that CLR antagonism of alcohol-induced BK channel inhibition requires cell integrity and is enabled by a PKC-dependent mechanism(s).
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Affiliation(s)
- Anna N Bukiya
- Dept. Pharmacology, Addiction Science, and Toxicology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States.
| | - Alex M Dopico
- Dept. Pharmacology, Addiction Science, and Toxicology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
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Kolczynska K, Loza-Valdes A, Hawro I, Sumara G. Diacylglycerol-evoked activation of PKC and PKD isoforms in regulation of glucose and lipid metabolism: a review. Lipids Health Dis 2020; 19:113. [PMID: 32466765 PMCID: PMC7257441 DOI: 10.1186/s12944-020-01286-8] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/14/2020] [Indexed: 12/15/2022] Open
Abstract
Protein kinase C (PKC) and Protein kinase D (PKD) isoforms can sense diacylglycerol (DAG) generated in the different cellular compartments in various physiological processes. DAG accumulates in multiple organs of the obese subjects, which leads to the disruption of metabolic homeostasis and the development of diabetes as well as associated diseases. Multiple studies proved that aberrant activation of PKCs and PKDs contributes to the development of metabolic diseases. DAG-sensing PKC and PKD isoforms play a crucial role in the regulation of metabolic homeostasis and therefore might serve as targets for the treatment of metabolic disorders such as obesity and diabetes.
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Affiliation(s)
- Katarzyna Kolczynska
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warszawa, Poland
| | - Angel Loza-Valdes
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warszawa, Poland
| | - Izabela Hawro
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warszawa, Poland
| | - Grzegorz Sumara
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur Street, 02-093, Warszawa, Poland.
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Mehta D, Mehta KD. PKCβ: Expanding role in hepatic adaptation of cholesterol homeostasis to dietary fat/cholesterol. Am J Physiol Gastrointest Liver Physiol 2017; 312:G266-G273. [PMID: 28104587 PMCID: PMC5401991 DOI: 10.1152/ajpgi.00373.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/11/2017] [Accepted: 01/17/2017] [Indexed: 01/31/2023]
Abstract
Cholesterol homeostasis relies on an intricate network of cellular processes whose deregulation in response to Western type high-fat/cholesterol diets can lead to several life-threatening pathologies. Significant advances have been made in resolving the molecular identity and regulatory function of transcription factors sensitive to fat, cholesterol, or bile acids, but whether body senses the presence of both fat and cholesterol simultaneously is not known. Assessing the impact of a high-fat/cholesterol load, rather than an individual component alone, on cholesterol homeostasis is more physiologically relevant because Western diets deliver both fat and cholesterol at the same time. Moreover, dietary fat and dietary cholesterol are reported to act synergistically to impair liver cholesterol homeostasis. A key insight into the role of protein kinase C-β (PKCβ) in hepatic adaptation to high-fat/cholesterol diets was gained recently through the use of knockout mice. The emerging evidence indicates that PKCβ is an important regulator of cholesterol homeostasis that ensures normal adaptation to high-fat/cholesterol intake. Consistent with this function, high-fat/cholesterol diets induce PKCβ expression and signaling in the intestine and liver, while systemic PKCβ deficiency promotes accumulation of cholesterol in the liver and bile. PKCβ disruption results in profound dysregulation of hepatic cholesterol and bile homeostasis and imparts sensitivity to cholesterol gallstone formation. The available results support involvement of a two-pronged mechanism by which intestine and liver PKCβ signaling converge on liver ERK1/2 to dictate diet-induced cholesterol and bile acid homeostasis. Collectively, PKCβ is an integrator of dietary fat/cholesterol signal and mediates changes to cholesterol homeostasis.
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Affiliation(s)
- Devina Mehta
- 1Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; and
| | - Kamal D. Mehta
- 2Department of Biological Chemistry and Pharmacology, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
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Alwarawrah M, Hussain F, Huang J. Alteration of lipid membrane structure and dynamics by diacylglycerols with unsaturated chains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:253-63. [PMID: 26607007 DOI: 10.1016/j.bbamem.2015.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/05/2015] [Accepted: 11/18/2015] [Indexed: 01/15/2023]
Abstract
Diacylglycerols (DAGs) with unsaturated acyl chains play many important roles in biomembranes, such as a second messenger and activator for protein kinase C. In this study, three DAGs of distinctly different chain unsaturations (i.e. di16:0DAG (DPG), 16:0-18:1DAG (POG), and di18:1DAG (DOG)) are studied using atomistic MD simulation to compare their roles in the structure and dynamics of 16:0-18:1phosphatidylcholine (POPC) membranes. All three DAGs are able to produce the so-called 'condensing effect' in POPC membranes: decreasing area-per-lipid, and increasing acyl chain order and bilayer thickness. Our visual and quantitative analyses clearly show that DAG with unsaturated chains induce larger spacing between POPC headgroups, compared with DAG with saturated chains; this particular effect has long been hypothesized to be crucial for activating enzymes and receptors in cell membranes. DAGs with unsaturated chains are also located closer to the bilayer/aqueous interface than DPG and are more effective in slowing down lateral diffusion of molecules. We show that DAG molecules seek the "umbrella coverage" from neighboring phospholipid headgroups - similar to cholesterol. Unlike cholesterol, DAGs also hide their chains from water by laterally inserting their chains into the surrounding. Thus, acyl chains of DAG are more spread and disordered than those of PC due to the insertion. By calculating the potential of mean force (PMF) for POPC in POPC/DAG bilayers, we found that all three DAGs can significantly increase the free energy barrier for POPC to flip-flop, but only DAGs with unsaturated chains can additionally increase the free energy of POPC desorption.
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Affiliation(s)
- Mohammad Alwarawrah
- Department of Physics, Texas Tech University, Lubbock, TX 79409, United States
| | - Fazle Hussain
- Department of Mechanical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Juyang Huang
- Department of Physics, Texas Tech University, Lubbock, TX 79409, United States.
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de Faria Poloni J, Bonatto D. Systems Chemo-Biology and Transcriptomic Meta-Analysis Reveal the Molecular Roles of Bioactive Lipids in Cardiomyocyte Differentiation. J Cell Biochem 2015; 116:2018-31. [PMID: 25752681 DOI: 10.1002/jcb.25156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 03/03/2015] [Indexed: 11/12/2022]
Abstract
Lipids, which are essential constituents of biological membranes, play structural and functional roles in the cell. In recent years, certain lipids have been identified as regulatory signaling molecules and have been termed "bioactive lipids". Subsequently, the importance of bioactive lipids in stem cell differentiation and cardiogenesis has gained increasing recognition. Therefore, the aim of this study was to identify the biological processes underlying murine cardiac differentiation and the mechanisms by which bioactive lipids affect these processes. For this purpose, a transcriptomic meta-analysis of microarray and RNA-seq data from murine stem cells undergoing cardiogenic differentiation was performed. The differentially expressed genes identified via this meta-analysis, as well as bioactive lipids, were evaluated using systems chemo-biology tools. These data indicated that bioactive lipids are associated with the regulation of cell motility, cell adhesion, cytoskeletal rearrangement, and gene expression. Moreover, bioactive lipids integrate the signaling pathways involved in cell migration, the secretion and remodeling of extracellular matrix components, and the establishment of the cardiac phenotype. In conclusion, this study provides new insights into the contribution of bioactive lipids to the induction of cellular responses to various stimuli, which may originate from the extracellular environment and morphogens, and the manner in which this contribution directly affects murine heart morphogenesis.
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Affiliation(s)
- Joice de Faria Poloni
- Centro de Biotecnologia da Universidade Federal do Rio Grande do Sul, Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Diego Bonatto
- Centro de Biotecnologia da Universidade Federal do Rio Grande do Sul, Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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10
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Petrov AM, Zakyrjanova GF, Yakovleva AA, Zefirov AL. Inhibition of protein kinase C affects on mode of synaptic vesicle exocytosis due to cholesterol depletion. Biochem Biophys Res Commun 2015; 456:145-50. [DOI: 10.1016/j.bbrc.2014.11.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 11/14/2014] [Indexed: 11/29/2022]
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11
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Zou J, Yue XY, Zheng SC, Zhang G, Chang H, Liao YC, Zhang Y, Xue MQ, Qi Z. Cholesterol modulates function of connexin 43 gap junction channel via PKC pathway in H9c2 cells. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2019-25. [PMID: 24780378 DOI: 10.1016/j.bbamem.2014.04.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 04/09/2014] [Accepted: 04/18/2014] [Indexed: 10/25/2022]
Abstract
It has been shown that cholesterol modulates activity of protein kinase C (PKC), and PKC phosphorylates connexin 43 (Cx43) to regulate its function, respectively. However, it is not known whether cholesterol modulates function of Cx43 through regulating activity of PKC. In the present study, we demonstrated that cholesterol enrichment reduced the dye transfer ability of Cx43 in cultured H9c2 cells. Western blot analysis indicated that cholesterol enrichment enhanced the phosphorylated state of Cx43. Immunofluorescent images showed that cholesterol enrichment made the Cx43 distribution from condensed to diffused manner in the interface between the cells. In cholesterol enriched cells, PKC antagonists partially restored the dye transfer ability among the cells, downregulated the phosphorylation of Cx43 and redistributed Cx43 from the diffused manner to the condensed manner in the cell interface. In addition, reduction of cholesterol level suppressed PKC activity to phosphorylate Cx43 and restored Cx43 function in PKC agonist-treated cells. Furthermore, we demonstrated that cholesterol enrichment upregulated the phosphorylated state of Cx43 at Ser368, while PKC antagonists reversed the effect. Taken together, cholesterol level in the cells plays important roles in regulating Cx43 function through activation of the PKC signaling pathway.
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Affiliation(s)
- Jun Zou
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China.
| | - Xiao-Yang Yue
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China
| | - Sheng-Chao Zheng
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China
| | - Guangwei Zhang
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China; Xiamen Heart Center, Zhongshan Hospital affiliated to Xiamen University, Xiamen 361004, China
| | - He Chang
- Xiamen Heart Center, Zhongshan Hospital affiliated to Xiamen University, Xiamen 361004, China
| | - Yan-Chun Liao
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China
| | - Ye Zhang
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China
| | - Mao-Qiang Xue
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China
| | - Zhi Qi
- Department of Basic Medical Sciences, Medical College, Xiamen University, Xiang'an Nan Lu, Xiamen 361102, China.
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Carrillo C, Hichami A, Andreoletti P, Cherkaoui-Malki M, del Mar Cavia M, Abdoul-Azize S, Alonso-Torre SR, Khan NA. Diacylglycerol-containing oleic acid induces increases in [Ca2+]i via TRPC3/6 channels in human T-cells. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:618-26. [DOI: 10.1016/j.bbalip.2012.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Revised: 01/06/2012] [Accepted: 01/10/2012] [Indexed: 10/14/2022]
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13
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Alwarawrah M, Dai J, Huang J. Modification of Lipid Bilayer Structure by Diacylglycerol: A Comparative Study of Diacylglycerol and Cholesterol. J Chem Theory Comput 2012; 8:749-758. [PMID: 22389636 PMCID: PMC3289152 DOI: 10.1021/ct200790q] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Diacylglycerols (DAGs) are important second messengers in biomembranes, and they can activate protein kinase C and many other enzymes and receptors. However, their interactions with cholesterol and other lipids have not been previously studied using molecular dynamics (MD) simulation. In this study, nine independent atomistic MD simulations were performed to specifically investigate the interactions between di16:0DAG, 16:0,18:1-phosphatidylcholine (POPC), and cholesterol. Despite of their substantial differences in chemical structure, DAG and cholesterol produce some very similar effects in POPC bilayers: increasing acyl chain order and bilayer thickness, reducing volume-per-lipid, and decreasing lateral diffusion of molecules. More significantly, DAG also produces a strong "condensing effect" in PC bilayers. In comparison, cholesterol is more effective than DAG in producing the above effects. The driving force for the condensing effect is their molecular shape: DAG and cholesterol both have small polar headgroups and large hydrophobic bodies. In a lipid bilayer, in order to avoid the unfavorable exposure of their hydrophobic parts to water, neighboring phospholipid headgroups move toward cholesterol or DAG to provide cover. Thus, seemingly complex interactions between DAG, cholesterol and phospholipid can be clearly explained using the Umbrella Model. Our simulations confirmed the hypothesis that DAG increases the spacing between phospholipid headgroups, which is important for activating protein kinase C and other enzymes. Interestingly, our simulations also show that the conventional wisdom that the spacing created by a DAG is directly above the DAG molecule is incorrect; instead, the largest spacing usually occurs between the first and the second nearest-neighbor PC headgroups from a DAG, due to the umbrella effect.
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Affiliation(s)
| | - Jian Dai
- Department of Physics Texas Tech University Lubbock, Texas 79409
| | - Juyang Huang
- Department of Physics Texas Tech University Lubbock, Texas 79409
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14
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Lee SY, Choi HK, Kim ST, Chung S, Park MK, Cho JH, Ho WK, Cho H. Cholesterol inhibits M-type K+ channels via protein kinase C-dependent phosphorylation in sympathetic neurons. J Biol Chem 2010; 285:10939-50. [PMID: 20123983 PMCID: PMC2856299 DOI: 10.1074/jbc.m109.048868] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 01/25/2010] [Indexed: 01/10/2023] Open
Abstract
M-type (KCNQ) potassium channels play an important role in regulating the action potential firing in neurons. Here, we investigated the effect of cholesterol on M current in superior cervical ganglion (SCG) sympathetic neurons, using the patch clamp technique. M current was inhibited in a dose-dependent manner by cholesterol loading with a methyl-beta-cyclodextrin-cholesterol complex. This effect was prevented when membrane cholesterol level was restored by including empty methyl-beta-cyclodextrin in the pipette solution. Dialysis of cells with AMP-PNP instead of ATP prevented cholesterol action on M currents. Protein kinase C (PKC) inhibitor, calphostin C, abolished cholesterol-induced inhibition whereas the PKC activator, PDBu, mimicked the inhibition of M currents by cholesterol. The in vitro kinase assay showed that KCNQ2 subunits of M channel can be phosphorylated by PKC. A KCNQ2 mutant that is defective in phosphorylation by PKC failed to show current inhibition not only by PDBu but also by cholesterol. These results indicate that cholesterol-induced inhibition of M currents is mediated by PKC phosphorylation. The inhibition of M currents by PDBu and cholesterol was completely blocked by PIP(2) loading, indicating that the decrease in PIP(2)-channel interaction underlies M channel inhibition by PKC-mediated phosphorylation. We conclude that cholesterol specifically regulates M currents in SCG neurons via PKC activation.
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Affiliation(s)
| | - Hyun-Kyung Choi
- Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea and
| | - Seong-Tae Kim
- Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea and
| | | | | | - Jung-Hwa Cho
- the WCU Neurocytomics Program Project, Department of Physiology, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul 110-799, Korea
| | - Won-Kyung Ho
- the WCU Neurocytomics Program Project, Department of Physiology, Seoul National University College of Medicine and Neuroscience Research Institute, Seoul 110-799, Korea
| | - Hana Cho
- From the Departments of Physiology and
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Chong PLG, Zhu W, Venegas B. On the lateral structure of model membranes containing cholesterol. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2-11. [DOI: 10.1016/j.bbamem.2008.10.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2008] [Revised: 10/18/2008] [Accepted: 10/20/2008] [Indexed: 10/21/2022]
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