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Cook-Mills JM, Averill SH, Lajiness JD. Asthma, allergy and vitamin E: Current and future perspectives. Free Radic Biol Med 2022; 179:388-402. [PMID: 34785320 PMCID: PMC9109636 DOI: 10.1016/j.freeradbiomed.2021.10.037] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/12/2021] [Accepted: 10/21/2021] [Indexed: 02/03/2023]
Abstract
Asthma and allergic disease result from interactions of environmental exposures and genetics. Vitamin E is one environmental factor that can modify development of allergy early in life and modify responses to allergen after allergen sensitization. Seemingly varied outcomes from vitamin E are consistent with the differential functions of the isoforms of vitamin E. Mechanistic studies demonstrate that the vitamin E isoforms α-tocopherol and γ-tocopherol have opposite functions in regulation of allergic inflammation and development of allergic disease, with α-tocopherol having anti-inflammatory functions and γ-tocopherol having pro-inflammatory functions in allergy and asthma. Moreover, global differences in prevalence of asthma by country may be a result, at least in part, of differences in consumption of these two isoforms of tocopherols. It is critical in clinical and animal studies that measurements of the isoforms of tocopherols be determined in vehicles for the treatments, and in the plasma and/or tissues before and after intervention. As allergic inflammation is modifiable by tocopherol isoforms, differential regulation by tocopherol isoforms provide a foundation for development of interventions to improve lung function in disease and raise the possibility of early life dietary interventions to limit the development of lung disease.
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Affiliation(s)
- Joan M Cook-Mills
- Herman B Wells Center for Pediatric Research, Departments of Pediatrics and Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
| | - Samantha H Averill
- Herman B Wells Center for Pediatric Research, Departments of Pediatrics and Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Jacquelyn D Lajiness
- Herman B Wells Center for Pediatric Research, Departments of Pediatrics and Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
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2
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Zheng X, Lu G, Yao Y, Gu W. An Autocrine IL-6/IGF-1R Loop Mediates EMT and Promotes Tumor Growth in Non-small Cell Lung Cancer. Int J Biol Sci 2019; 15:1882-1891. [PMID: 31523190 PMCID: PMC6743301 DOI: 10.7150/ijbs.31999] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 05/25/2019] [Indexed: 12/17/2022] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) is a key process in EGFR-TKI resistance but the detailed mechanism is largely unknown. We aim to evaluate the role of interleukin-6 (IL-6) and insulin-like growth factor-1 receptor (IGR-1R) in EMT in non-small cell lung cancer (NSCLC). We used IL-6 to induce EMT in EGFR-TKI sensitive NSCLC cells. We found that both STAT3 and IGF-1R were activated. Interestingly activation of STAT3 and JAK1 was blocked by inhibiting IGF-1R, suggesting that IGF-1R might signal via JAK/STAT3. Activation of IGF-1R and AKT was inhibited by blocking STAT3, suggesting that STAT3 blockade might provide negative feedback signal to inhibiting IGF-1R. Reporter assay further confirmed that STAT3 activated gene transcription of IGF-1R. RT-PCR analyses showed that IL-6 induced the expression of IL-6 per se as well as IGF-1 and IGF-2. Expression of IL-6 and IGF-1R ligands was suppressed by inhibiting either STAT3 or IGF-1R. Meanwhile IL-6 induced gefitinib resistance and increased migration. We elucidated an autocrine loop of IL-6/IGF-1R/STAT3 in EMT-mediated resistance and tumor growth in NSCLC.
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Affiliation(s)
- Xianan Zheng
- Department of Endocrinology, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Guohua Lu
- Department of Respiratory Diseases, the First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Yinan Yao
- Department of Respiratory Diseases, the First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Wei Gu
- Department of Endocrinology, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
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3
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Liang Q, Ou M, Ren Y, Yao Z, Hu R, Li J, Liu Y, Wang W. Molecular cloning, characterization and expression analysis of S- adenosyl- L-homocysteine hydrolase (SAHH) during the pathogenic infection of Litopenaeus vannamei by Vibrio alginolyticus. FISH & SHELLFISH IMMUNOLOGY 2019; 88:284-292. [PMID: 30849500 DOI: 10.1016/j.fsi.2019.02.058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 06/09/2023]
Abstract
SAHH is an enzyme, playing a significant role in the catalyzation of the S-adenosyl homocysteine (SAH) into homocysteine (Hcy) and adenosine (Ado). However, little is known information of the enzyme in crustaceans. In the present study, SAHH cDNA was cloned from Litopenaeus vannamei (LvSAHH). The full length of the LvSAHH was found, containing a 5' UTR of 119 bp, an ORF of 1236 bp and a 3' UTR of 549 bp. The LvSAHH gene encoded a polypeptide of 411 amino acids with an estimated molecular mass of 45.55 kD and a predicted isoelectronic point (pI) of 5.63. Comparison of the deduced amino acid sequence showed that LvSAHH has high identity (70 %-82%) with other known species. qRT-PCR analysis revealed that LvSAHH mRNA was broadly expressed in all of the examined tissues, while the highest expression level was observed in muscle, followed by the expression in stomach, gill, pleopod, hepatopancreas, heart, eye and intestine. Subcellular localization analysis revealed that LvSAHH was predominantly localized in the cytoplasm and nucleus. LvSAHH mRNA expression levels in hepatopancreas and gill were significantly up-regulated from 6 to 48 h after V. alginolyticus injection and reached the highest level (15-fold and 8-fold, p < 0.01) at 24 h, respectively. Additionally, the Toll-like receptors (TLR) and interleukins-16 (IL-16) were detected in hepatopancreas and gill of LvSAHH-knockdown SAHH. LvRack1, LvToll1, LvToll2, LvToll3 and LvIL-16 transcripts were decreased significantly in LvSAHH-knockdown shrimp at 24 h post V. alginolyticus stimulation in hepatopancreas and gill. But LvToll3 was no significant difference in gill. In summary, these results indicated that LvSAHH may play a regulatory role in the invertebrate innate immune defense by regulating TLR and IL-16 expression.
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Affiliation(s)
- QingJian Liang
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - MuFei Ou
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - YingHao Ren
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - ZeNa Yao
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - Rui Hu
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - JieZhen Li
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - Yuan Liu
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China
| | - Weina Wang
- College of Life Science, South China Normal University, Guangzhou, 510631, PR China; Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, PR China; Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, PR China.
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4
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Lu W, Guo B, Wang X, Xu K, Qi P. The receptor for activated C kinase 1 (RACK1) mediating immune response in thick shell mussel Mytilus coruscus. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 85:61-70. [PMID: 29649551 DOI: 10.1016/j.dci.2018.04.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 04/02/2018] [Accepted: 04/05/2018] [Indexed: 06/08/2023]
Abstract
The receptor for activated C kinase 1 (RACK1) is a intracellular receptor for the protein kinase C family which mediates various biological processes. Here, a novel RACK1 gene termed Mc-RACK1 was identified from thick shell mussel, Mytilus coruscus. Mc-RACK1 shared typical RACK1 domains containing WD repeats, PKC phosphorylation sites, N-myristoylation sites, PKC activation sites, TK phosphorylation site and WD motifs. Mc-RACK1 was constitutively expressed in all examined tissues, and its expression in gills, haemocytes and digestive glands were significantly up-regulated upon LPS challenge. Mc-RACK1 showed a significantly down-regulated expression in gills and haemocytes at the early phase upon copper exposure. Mc-RACK1 in haemocytes was silenced after receiving its dsRNA, meanwhile, the increases of SOD and CAT activity were investigated. Further, Mc-RACK1 could activate the NF-κB and ISRE reporter in HEK-293T cells. These suggested that Mc-RACK1 had a deeper involvement in mollusc immunity, and played an important role in antioxidant system.
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Affiliation(s)
- Weixiao Lu
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, 316004, China
| | - Baoying Guo
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, 316004, China
| | - Xiaoyan Wang
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, 316004, China
| | - Kaida Xu
- Key Laboratory of Sustainable Utilization of Technology Research, Marine Fisheries Research Institute of Zhejiang, Zhoushan, 316021, China
| | - Pengzhi Qi
- National Engineering Research Center of Marine Facilities Aquaculture, Marine Science and Technology College, Zhejiang Ocean University, Zhoushan, 316004, China.
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5
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Pizzino G, Irrera N, Cucinotta M, Pallio G, Mannino F, Arcoraci V, Squadrito F, Altavilla D, Bitto A. Oxidative Stress: Harms and Benefits for Human Health. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:8416763. [PMID: 28819546 PMCID: PMC5551541 DOI: 10.1155/2017/8416763] [Citation(s) in RCA: 1835] [Impact Index Per Article: 262.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/05/2017] [Indexed: 02/07/2023]
Abstract
Oxidative stress is a phenomenon caused by an imbalance between production and accumulation of oxygen reactive species (ROS) in cells and tissues and the ability of a biological system to detoxify these reactive products. ROS can play, and in fact they do it, several physiological roles (i.e., cell signaling), and they are normally generated as by-products of oxygen metabolism; despite this, environmental stressors (i.e., UV, ionizing radiations, pollutants, and heavy metals) and xenobiotics (i.e., antiblastic drugs) contribute to greatly increase ROS production, therefore causing the imbalance that leads to cell and tissue damage (oxidative stress). Several antioxidants have been exploited in recent years for their actual or supposed beneficial effect against oxidative stress, such as vitamin E, flavonoids, and polyphenols. While we tend to describe oxidative stress just as harmful for human body, it is true as well that it is exploited as a therapeutic approach to treat clinical conditions such as cancer, with a certain degree of clinical success. In this review, we will describe the most recent findings in the oxidative stress field, highlighting both its bad and good sides for human health.
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Affiliation(s)
- Gabriele Pizzino
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Natasha Irrera
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Mariapaola Cucinotta
- Department of Biomedical Sciences, Dentistry and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Giovanni Pallio
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Federica Mannino
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Vincenzo Arcoraci
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Francesco Squadrito
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Domenica Altavilla
- Department of Biomedical Sciences, Dentistry and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Alessandra Bitto
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
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6
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Bolger GB. The RNA-binding protein SERBP1 interacts selectively with the signaling protein RACK1. Cell Signal 2017; 35:256-263. [PMID: 28267599 DOI: 10.1016/j.cellsig.2017.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 02/23/2017] [Accepted: 03/02/2017] [Indexed: 12/19/2022]
Abstract
The RACK1 protein interacts with numerous proteins involved in signal transduction, the cytoskeleton, and mRNA splicing and translation. We used the 2-hybrid system to identify additional proteins interacting with RACK1 and isolated the RNA-binding protein SERBP1. SERPB1 shares amino acid sequence homology with HABP4 (also known as Ki-1/57), a component of the RNA spicing machinery that has been shown previously to interact with RACK1. Several different isoforms of SERBP1, generated by alternative mRNA splicing, interacted with RACK1 with indistinguishable interaction strength, as determined by a 2-hybrid beta-galactosidase assay. Analysis of deletion constructs of SERBP1 showed that the C-terminal third of the SERBP1 protein, which contains one of its two substrate sites for protein arginine N-methyltransferase 1 (PRMT1), is necessary and sufficient for it to interact with RACK1. Analysis of single amino acid substitutions in RACK1, identified in a reverse 2-hybrid screen, showed very substantial overlap with those implicated in the interaction of RACK1 with the cAMP-selective phosphodiesterase PDE4D5. These data are consistent with SERBP1 interacting selectively with RACK1, mediated by an extensive interaction surface on both proteins.
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Affiliation(s)
- Graeme B Bolger
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294-3300, USA; Department of Pharmacology, University of Alabama at Birmingham, Birmingham, AL 35294-3300, USA.
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7
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Galli F, Azzi A, Birringer M, Cook-Mills JM, Eggersdorfer M, Frank J, Cruciani G, Lorkowski S, Özer NK. Vitamin E: Emerging aspects and new directions. Free Radic Biol Med 2017; 102:16-36. [PMID: 27816611 DOI: 10.1016/j.freeradbiomed.2016.09.017] [Citation(s) in RCA: 256] [Impact Index Per Article: 36.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/11/2016] [Accepted: 09/22/2016] [Indexed: 12/30/2022]
Abstract
The discovery of vitamin E will have its 100th anniversary in 2022, but we still have more questions than answers regarding the biological functions and the essentiality of vitamin E for human health. Discovered as a factor essential for rat fertility and soon after characterized for its properties of fat-soluble antioxidant, vitamin E was identified to have signaling and gene regulation effects in the 1980s. In the same years the cytochrome P-450 dependent metabolism of vitamin E was characterized and a first series of studies on short-chain carboxyethyl metabolites in the 1990s paved the way to the hypothesis of a biological role for this metabolism alternative to vitamin E catabolism. In the last decade other physiological metabolites of vitamin E have been identified, such as α-tocopheryl phosphate and the long-chain metabolites formed by the ω-hydroxylase activity of cytochrome P-450. Recent findings are consistent with gene regulation and homeostatic roles of these metabolites in different experimental models, such as inflammatory, neuronal and hepatic cells, and in vivo in animal models of acute inflammation. Molecular mechanisms underlying these responses are under investigation in several laboratories and side-glances to research on other fat soluble vitamins may help to move faster in this direction. Other emerging aspects presented in this review paper include novel insights on the mechanisms of reduction of the cardiovascular risk, immunomodulation and antiallergic effects, neuroprotection properties in models of glutamate excitotoxicity and spino-cerebellar damage, hepatoprotection and prevention of liver toxicity by different causes and even therapeutic applications in non-alcoholic steatohepatitis. We here discuss these topics with the aim of stimulating the interest of the scientific community and further research activities that may help to celebrate this anniversary of vitamin E with an in-depth knowledge of its action as vitamin.
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Affiliation(s)
- Francesco Galli
- Department of Pharmaceutical Sciences, University of Perugia, Laboratory of Clinical Biochemistry and Nutrition, Via del Giochetto, 06126 Perugia, Italy.
| | - Angelo Azzi
- USDA-HNRCA at Tufts University, 711 Washington St., Boston, MA 02111, United States.
| | - Marc Birringer
- Department of Nutritional, Food and Consumer Sciences, Fulda University of Applied Sciences, Leipziger Straße 123, 36037 Fulda, Germany.
| | - Joan M Cook-Mills
- Allergy/Immunology Division, Northwestern University, 240 E Huron, Chicago, IL 60611, United States.
| | | | - Jan Frank
- Institute of Biological Chemistry and Nutrition, University of Hohenheim, Garbenstr. 28, 70599 Stuttgart, Germany.
| | - Gabriele Cruciani
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Italy.
| | - Stefan Lorkowski
- Institute of Nutrition, Friedrich Schiller University Jena, Dornburger Str. 25, 07743 Jena, Germany; Competence Cluster for Nutrition and Cardiovascular Health (nutriCARD), Halle-Jena-Leipzig, Germany.
| | - Nesrin Kartal Özer
- Department of Biochemistry, Faculty of Medicine, Genetic and Metabolic Diseases Research Center (GEMHAM), Marmara University, 34854 Maltepe, Istanbul, Turkey.
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8
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Jia Z, Wang M, Wang X, Wang L, Song L. The receptor for activated C kinase 1 (RACK1) functions in hematopoiesis through JNK activation in Chinese mitten crab Eriocheir sinensis. FISH & SHELLFISH IMMUNOLOGY 2016; 57:252-261. [PMID: 27542616 DOI: 10.1016/j.fsi.2016.08.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 08/08/2016] [Accepted: 08/13/2016] [Indexed: 06/06/2023]
Abstract
Receptor for activated C kinase 1 (RACK1) is a WD-domain repeating protein which involves in the mediation of various biological processes, including innate immune response. In the present study, a RACK1 (designed as EsRACK1) gene from Chinese mitten crab E. sinensis was cloned by rapid amplification of cDNA ends (RACE) technique. The full-length cDNA sequence of EsRACK1 was of 1117 bp with an open reading frame (ORF) of 957 bp encoding a polypeptide of 318 amino acids containing seven WD repeats. EsRACK1 shared 62%-99% similarities with previously identified RACK1s in amino acid sequence, and it was clustered with the RACK1 from Pacifastacus leniusculus in the phylogenetic tree. The mRNA transcripts of EsRACK1 were constitutively expressed in various tissues with the highest expression level in hepatopancreas. The expression of EsRACK1 mRNA in hemocytes were significantly up-regulated post the stimulations with Vibrio anguillarum and Pichia pastoris. After exposure to CdCl2 and pentachlorophenol, the transcripts of EsRACK1 in hemocytes were up-regulated at the late phase from 12 h. When EsRACK1 was knocked down by dsRNA based RNAi, the total hemocyte counts, new-born hemocytes and phosphorylation of JNK were all significantly decreased. In addition, EsRACK1 transcription and phosphorylation of JNK were both decreased in hematopoietic tissue post Aeromonas hydrophila challenge. All the results suggested that EsRACK1 was involved in the innate immune response of the crab and participated in the production of new-born hemocytes through activation of JNK.
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MESH Headings
- Aeromonas hydrophila/physiology
- Amino Acid Sequence
- Animals
- Arthropod Proteins/chemistry
- Arthropod Proteins/genetics
- Arthropod Proteins/metabolism
- Base Sequence
- Brachyura/drug effects
- Brachyura/genetics
- Brachyura/immunology
- Brachyura/microbiology
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Hematopoiesis/drug effects
- Herbicides/toxicity
- Immunity, Innate
- Metals, Heavy/toxicity
- Phylogeny
- Pichia/physiology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors for Activated C Kinase
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Sequence Alignment
- Tissue Distribution
- Up-Regulation
- Vibrio/physiology
- Water Pollutants, Chemical/toxicity
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Affiliation(s)
- Zhihao Jia
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengqiang Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xiudan Wang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lingling Wang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China
| | - Linsheng Song
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
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9
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Gallo S, Manfrini N. Working hard at the nexus between cell signaling and the ribosomal machinery: An insight into the roles of RACK1 in translational regulation. ACTA ACUST UNITED AC 2015; 3:e1120382. [PMID: 26824030 DOI: 10.1080/21690731.2015.1120382] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/19/2015] [Accepted: 11/09/2015] [Indexed: 02/08/2023]
Abstract
RACK1 is a ribosome-associated protein which functions as a receptor for activated PKCs. It also acts as a scaffold for many other proteins involved in diverse signaling pathways, e.g. Src, JNK, PDE4D and FAK signaling. With such a broad interactome, RACK1 has been suggested to function as a linker between cell signaling and the translation machinery. Accordingly, RACK1 modulates translation at different levels in several model organisms. For instance, it regulates ribosome stalling and mRNA quality control in yeasts and promotes translation efficiency downstream of specific cellular stimuli in mammals. However, the molecular mechanism by which RACK1 exerts these roles is widely uncharacterized. Moreover, the full list of ribosome-recruited RACK1 interactors still needs characterization. Here we discuss in vivo and in vitro findings to better delineate the roles of RACK1 in regulating ribosome function and translation.
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Affiliation(s)
- Simone Gallo
- Molecular Histology and Cell Growth Unit; National Institute of Molecular Genetics - INGM "Romeo and Enrica Invernizzi" ; Milan, Italy
| | - Nicola Manfrini
- Molecular Histology and Cell Growth Unit; National Institute of Molecular Genetics - INGM "Romeo and Enrica Invernizzi" ; Milan, Italy
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10
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Intranasal immunisation of the recombinant Toxoplasma gondii receptor for activated C kinase 1 partly protects mice against T. gondii infection. Acta Trop 2014; 137:58-66. [PMID: 24813415 DOI: 10.1016/j.actatropica.2014.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 04/30/2014] [Accepted: 05/01/2014] [Indexed: 12/27/2022]
Abstract
Nasal vaccination is an effective therapeutic regimen for preventing certain infectious diseases. The mucosal immune response is important for resistance to Toxoplasma gondii infection. In this study, we evaluated the immune responses elicited in BALB/c mice by nasal immunisation with recombinant T. gondii receptor for activated C kinase 1 (rTgRACK1) and their protective efficacy against T. gondii RH strain during both chronic and lethal infections. Nasal vaccination with rTgRACK1 increased the level of secretory IgA in nasal, intestinal and vesical washes, and the level of IFN-γ and IL-2 in intestinal washes, indicating that rTgRACK1 vaccination promotes mucosal immune responses. The mice immunised with rTgRACK1 also displayed increased levels of rTgRACK1-specific IgA, total IgG, IgG1 and in particular IgG2a in their blood sera, increased production of IFN-γ, IL-2 and IL-4 but not IL-10 from their isolated spleen cells, and enhanced splenocyte proliferation in vitro. rTgRACK1-vaccinated mice were effectively protected against infection with T. gondii RH strain, showing over 50% reduction of tachyzoite burdens in their liver and brain tissues during a chronic infection, and also a 45% increase in their survivals during a lethal challenge. These results indicate that rTgRACK1 might represent an intriguing immunogen for developing a mucosal vaccine against toxoplasmosis.
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11
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Identification of a new Mpl-interacting protein, Atp5d. Mol Cell Biochem 2014; 391:85-94. [PMID: 24615392 DOI: 10.1007/s11010-014-1990-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 01/29/2014] [Indexed: 10/25/2022]
Abstract
Thrombopoietin (TPO) can regulate hematopoiesis and megakaryopoiesis via activation of its receptor, c-Mpl, and multiple downstream signal transduction pathways. Using the cytoplasmic domain of Mpl as bait, we performed yeast two-hybrid screening, and found that the protein Atp5d might associate with Mpl. Atp5d is known as the δ subunit of mitochondrial ATP synthase, but little is known about the function of dissociative Atp5d. The interaction between Mpl and Atp5d was confirmed by the yeast two-hybrid system, mammalian two-hybrid assay, pull-down experiment, and co-immunoprecipitation study in vivo and in vitro. An additional immunofluorescence assay showed that the two proteins can colocalize along the plasma membrane in the cytoplasm. Using the yeast two-hybrid system, we tested a series of cytoplasmic truncated mutations for their ability to bind Atp5d and found an association between Atp5d and the Aa98-113 domain of Mpl. The dissociation of Atp5d from Mpl after TPO stimulation suggests that Atp5d may be a new component of TPO signaling.
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12
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Farren MR, Carlson LM, Netherby CS, Lindner I, Li PK, Gabrilovich DI, Abrams SI, Lee KP. Tumor-induced STAT3 signaling in myeloid cells impairs dendritic cell generation by decreasing PKCβII abundance. Sci Signal 2014; 7:ra16. [PMID: 24550541 DOI: 10.1126/scisignal.2004656] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A major mechanism by which cancers escape control by the immune system is by blocking the differentiation of myeloid cells into dendritic cells (DCs), immunostimulatory cells that activate antitumor T cells. Tumor-dependent activation of signal transducer and activator of transcription 3 (STAT3) signaling in myeloid progenitor cells is thought to cause this block in their differentiation. In addition, a signaling pathway through protein kinase C βII (PKCβII) is essential for the differentiation of myeloid cells into DCs. We found in humans and mice that breast cancer cells substantially decreased the abundance of PKCβII in myeloid progenitor cells through a mechanism involving the enhanced activation of STAT3 signaling by soluble, tumor-derived factors (TDFs). STAT3 bound to previously undescribed negative regulatory elements within the promoter of PRKCB, which encodes PKCβII. We also found a previously undescribed counter-regulatory mechanism through which the activity of PKCβII inhibited tumor-dependent STAT3 signaling by decreasing the abundance of cell surface receptors, such as cytokine and growth factor receptors, that are activated by TDFs. Together, these data suggest that a previously unrecognized cross-talk mechanism between the STAT3 and PKCβII signaling pathways provides the molecular basis for the tumor-induced blockade in the differentiation of myeloid cells, and suggest that enhancing PKCβII activity may be a therapeutic strategy to alleviate cancer-mediated suppression of the immune system.
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Affiliation(s)
- Matthew R Farren
- 1Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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Matsumoto T, Hasegawa H, Onishi S, Ishizaki J, Suemori K, Yasukawa M. Protein kinase C inhibitor generates stable human tolerogenic dendritic cells. THE JOURNAL OF IMMUNOLOGY 2013; 191:2247-57. [PMID: 23878315 DOI: 10.4049/jimmunol.1203053] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Tolerogenic dendritic cells (DCs) are a promising tool for a specific form of cellular therapy whereby immunological tolerance can be induced in the context of transplantation and autoimmunity. From libraries of bioactive lipids, nuclear receptor ligands, and kinase inhibitors, we screened conventional protein kinase C inhibitors (PKCIs) bisindolylmaleimide I, Gö6983, and Ro32-0432 with strong tolerogenic potential. PKCI-treated human DCs were generated by subjecting them to a maturation process after differentiation of immature DCs. The PKCI-treated DCs had a semimature phenotype, showing high production of IL-10, and efficiently induced IL-10-producing T cells and functional Foxp3(+) regulatory T cells from naive CD4(+) T cells, thus eliciting a strong immunosuppressive function. They also showed CCR7 expression and sufficient capacity for migration toward CCR7 ligands. Additionally, PKCI-treated DCs were highly stable when exposed to inflammatory stimuli such as proinflammatory cytokines or LPS. Conventional PKCIs inhibited NF-κB activation of both the canonical and noncanonical pathways of DC maturation, thus suppressing the expression of costimulatory molecules and IL-12 production. High production of IL-10 in PKCI-treated DCs was due to not only an increase of intracellular cAMP, but also a synergistic effect of increased cAMP and NF-κB inhibition. Moreover, PKCI-treated mouse DCs that had properties similar to PKCI-treated human DCs prevented graft-versus-host disease in a murine model of acute graft-versus-host disease. Conventional PKCI-treated DCs may be useful for tolerance-inducing therapy, as they satisfy the required functional characteristics for clinical-grade tolerogenic DCs.
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Affiliation(s)
- Takuya Matsumoto
- Department of Bioregulatory Medicine, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan
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14
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Chen J, Liu J, Xiao S, Yu Z. Molecular cloning, characterization and expression analysis of receptor for activated C kinase 1 (RACK1) from pearl oyster (Pinctada martensii) challenged with bacteria and exposed to cadmium. FISH & SHELLFISH IMMUNOLOGY 2011; 31:781-787. [PMID: 21782956 DOI: 10.1016/j.fsi.2011.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 07/08/2011] [Accepted: 07/10/2011] [Indexed: 05/31/2023]
Abstract
Receptor for activated C kinase 1 (RACK1) is involved in superoxide anion generation and play an important role in the immune response. In the study, we cloned the full-length sequence of pearl oyster, Pinctada martensii, RACK1 (designated as PmRACK1) by a combination of expression sequence tag (EST) analysis and rapid amplification of cDNA ends (RACE). The full-length cDNA of PmRACK1 is 1176 bp in length, containing a 5' UTR of 83 bp, a 3' UTR of 139, and an open reading frame (ORF) of 954 bp encoding 317 amino acids. Analysis of protein domain features showed that the deduced polypeptide contain seven WD domains characteristic of RACK1 protein family. The tissue distribution of PmRACK1 in unchallenged pearl oysters and temporal expression pattern of PmRACK1 in pearl oysters challenged with bacteria and exposed to 0.1 ppm cadmium were analyzed by quantitative real-time PCR (qRT-PCR). The transcript was detected in all tissues tested, and the expression level was highest in hepatopancreas and lowest in adductor muscle. After challenge with bacteria, expression level of PmRACK1 in haemocytes was gradually decreased until 6 h post challenge, and then up-regulated over time. After exposure to cadmium, its expression level in gill decreased on 1 d post exposure, and then increased as time elapsed, and its expression level in hepatopancreas gradually decreased until 2 d post exposure, and then increased over time. These results suggested that PmRACK1 was involved in oxidative stress response caused by bacteria and cadmium and was a useful biomarker for cadmium exposure. The expression pattern of PmRACK1 in response to bacterial challenge also has a potential link with organism's immune response.
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Affiliation(s)
- Jinhui Chen
- Key Laboratory of Marine Bio-resources Sustainable Utilization, CAS, Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, Guangdong, China
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15
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Adams DR, Ron D, Kiely PA. RACK1, A multifaceted scaffolding protein: Structure and function. Cell Commun Signal 2011; 9:22. [PMID: 21978545 PMCID: PMC3195729 DOI: 10.1186/1478-811x-9-22] [Citation(s) in RCA: 330] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Accepted: 10/06/2011] [Indexed: 12/17/2022] Open
Abstract
The Receptor for Activated C Kinase 1 (RACK1) is a member of the tryptophan-aspartate repeat (WD-repeat) family of proteins and shares significant homology to the β subunit of G-proteins (Gβ). RACK1 adopts a seven-bladed β-propeller structure which facilitates protein binding. RACK1 has a significant role to play in shuttling proteins around the cell, anchoring proteins at particular locations and in stabilising protein activity. It interacts with the ribosomal machinery, with several cell surface receptors and with proteins in the nucleus. As a result, RACK1 is a key mediator of various pathways and contributes to numerous aspects of cellular function. Here, we discuss RACK1 gene and structure and its role in specific signaling pathways, and address how posttranslational modifications facilitate subcellular location and translocation of RACK1. This review condenses several recent studies suggesting a role for RACK1 in physiological processes such as development, cell migration, central nervous system (CN) function and circadian rhythm as well as reviewing the role of RACK1 in disease.
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Affiliation(s)
- David R Adams
- Department of Life Sciences, and Materials and Surface Science Institute, University of Limerick, Limerick, Ireland.
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Pazdrak K, Young TW, Straub C, Stafford S, Kurosky A. Priming of eosinophils by GM-CSF is mediated by protein kinase CbetaII-phosphorylated L-plastin. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2011; 186:6485-96. [PMID: 21525390 PMCID: PMC3100773 DOI: 10.4049/jimmunol.1001868] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The priming of eosinophils by cytokines leading to augmented response to chemoattractants and degranulating stimuli is a characteristic feature of eosinophils in the course of allergic inflammation and asthma. Actin reorganization and integrin activation are implicated in eosinophil priming by GM-CSF, but their molecular mechanism of action is unknown. In this regard, we investigated the role of L-plastin, an eosinophil phosphoprotein that we identified from eosinophil proteome analysis. Phosphoproteomic analysis demonstrated the upregulation of phosphorylated L-plastin after eosinophil stimulation with GM-CSF. Additionally, coimmunoprecipitation studies demonstrated a complex formation of phosphorylated L-plastin with protein kinase CβII (PKCβII), GM-CSF receptor α-chain, and two actin-associated proteins, paxilin and cofilin. Inhibition of PKCβII with 4,5-bis(4-fluoroanilino)phtalimide or PKCβII-specific small interfering RNA blocked GM-CSF-induced phosphorylation of L-plastin. Furthermore, flow cytometric analysis also showed an upregulation of α(M)β(2) integrin, which was sensitive to PKCβII inhibition. In chemotaxis assay, GM-CSF treatment allowed eosinophils to respond to lower concentrations of eotaxin, which was abrogated by the above-mentioned PKCβII inhibitors. Similarly, inhibition of PKCβII blocked GM-CSF induced priming for degranulation as assessed by release of eosinophil cationic protein and eosinophil peroxidase in response to eotaxin. Importantly, eosinophil stimulation with a synthetic L-plastin peptide (residues 2-19) phosphorylated on Ser(5) upregulated α(M)β(2) integrin expression and increased eosinophil migration in response to eotaxin independent of GM-CSF stimulation. Our results establish a causative role for PKCβII and L-plastin in linking GM-CSF-induced eosinophil priming for chemotaxis and degranulation to signaling events associated with integrin activation via induction of PKCβII-mediated L-plastin phosphorylation.
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Affiliation(s)
- Konrad Pazdrak
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
- UTMB National Heart, Lung, and Blood Institute Proteomics Center, University of Texas Medical Branch, Galveston, TX 77555
| | - Travis W. Young
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
- UTMB National Heart, Lung, and Blood Institute Proteomics Center, University of Texas Medical Branch, Galveston, TX 77555
| | - Christof Straub
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
- UTMB National Heart, Lung, and Blood Institute Proteomics Center, University of Texas Medical Branch, Galveston, TX 77555
| | - Susan Stafford
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
- UTMB National Heart, Lung, and Blood Institute Proteomics Center, University of Texas Medical Branch, Galveston, TX 77555
| | - Alexander Kurosky
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555
- UTMB National Heart, Lung, and Blood Institute Proteomics Center, University of Texas Medical Branch, Galveston, TX 77555
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17
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Farren MR, Carlson LM, Lee KP. Tumor-mediated inhibition of dendritic cell differentiation is mediated by down regulation of protein kinase C beta II expression. Immunol Res 2010; 46:165-76. [PMID: 19756409 DOI: 10.1007/s12026-009-8118-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tumor-mediated immune suppression occurs through multiple mechanisms, including dysregulation of dendritic cell differentiation. This block in differentiation results in fewer dendritic cells and an accumulation of immunosuppressive myeloid- derived suppressor cells and is thought to contribute to tumor outgrowth and to act as an impediment to successful anti-cancer immunotherapy. Tumor-mediated myeloid dysregulation is known to be Stat3 dependent; however, the molecular mechanism of this Stat3 signaling remains poorly defined. We have previously shown that PKC betaII is required for dendritic cell differentiation. Here, we describe our finding that tumors mediate both Stat3 activation and PKC betaII down regulation in DC progenitor cells, a process mimicked by the expression of a constitutive active Stat3 mutant. This demonstrates that tumor-mediated myeloid dysregulation may be mediated by Stat3- induced PKC betaII down regulation.
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Affiliation(s)
- Matthew R Farren
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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18
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Xu Y, Wang N, Ling F, Li P, Gao Y. Receptor for activated C-kinase 1, a novel binding partner of adiponectin receptor 1. Biochem Biophys Res Commun 2008; 378:95-8. [PMID: 19010305 DOI: 10.1016/j.bbrc.2008.11.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Accepted: 11/04/2008] [Indexed: 11/29/2022]
Abstract
Adiponectin is an adipose tissue derived hormone with anti-diabetic and insulin-sensitizing properties. Two adiponectin receptors, AdipoR1 and AdipoR2, have recently been identified, yet the signaling pathways triggered through adiponectin receptors remain to be elucidated. Using a yeast two-hybrid screen, we identified an adaptor protein, receptor for activated protein kinase C1 (RACK1), as an interacting partner of human AdipoR1. RACK1 was confirmed to interact with AdipoR1 by co-immunoprecipitation and co-localization analysis in mammalian cells. The interaction was enhanced by adiponectin stimulation. In addition, the knockdown of RACK1 by RNA interference inhibited adiponectin-stimulated glucose uptake in HepG2 cells. These results suggest that RACK1 may act as a key bridging factor in adiponectin signaling transduction through interacting with AdipoR1.
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Affiliation(s)
- Yizhou Xu
- Department of Cardiology, Hangzhou the First People's Hospital, 261 Wansha Road, Hangzhou 310006, China
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19
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Lindner I, Cejas PJ, Carlson LM, Torruellas J, Plano GV, Lee KP. Signal transduction in DC differentiation: winged messengers and Achilles' heel. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 590:1-29. [PMID: 17191374 DOI: 10.1007/978-0-387-34814-8_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Inna Lindner
- University of Miami Miller School of Medicine, Miami, FL 33136, USA
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20
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Redig AJ, Platanias LC. The protein kinase C (PKC) family of proteins in cytokine signaling in hematopoiesis. J Interferon Cytokine Res 2007; 27:623-36. [PMID: 17784814 DOI: 10.1089/jir.2007.0007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The members of the protein kinase C (PKC) family of proteins play important roles in signaling for various growth factors, cytokines, and hormones. Extensive work over the years has led to the identification of three major groups of PKC isoforms. These include the classic PKCs (PKCalpha, PKCbeta(I), PKCbeta(II), PKCgamma), the novel PKCs (PKCdelta, PKCepsilon, PKCeta, PKCmu, PKCtheta), and the atypical PKCs (PKCzeta, PKCiota/lambda). All these PKC subtypes have been shown to participate in the generation of signals for important cellular processes and to mediate diverse and, in some cases, opposing biologic responses. There is emerging evidence that these kinases also play key functional roles in the regulation of cell growth, apoptosis, and differentiation of hematopoietic cells. In this review, both the engagement of the various PKC members in cytokine and growth factor signaling and their role in the regulation of hematopoiesis are discussed.
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Affiliation(s)
- Amanda J Redig
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology-Oncology, Northwestern University Medical School, 300 East Superior Street, Chicago, IL 60611, USA
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21
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O'Donovan HC, Kiely PA, O'Connor R. Effects of RACK1 on cell migration and IGF-I signalling in cardiomyoctes are not dependent on an association with the IGF-IR. Cell Signal 2007; 19:2588-95. [PMID: 17900863 DOI: 10.1016/j.cellsig.2007.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Accepted: 08/14/2007] [Indexed: 10/22/2022]
Abstract
RACK1 can act as a scaffolding protein to integrate IGF-IR and integrin signalling in transformed cells but its actions in regulating IGF-IR signalling in non-transformed cells are less well understood. Here, we investigated the function of RACK1 in the non-transformed cardiomyocyte cell line H9c2. Overexpression of RACK1 in H9c2 cells was sufficient to increase cell size, increase adhesion to collagen 1, enhance protection from hydrogen peroxide-induced cell death, and increase cell migration. However, cell proliferation was decreased in these cells. Small interfering RNA (siRNA)-mediated suppression of RACK1 in H9c2 cells resulted in decreased cell adhesion and migration, but had no effect on cell proliferation or size. Increased basal and IGF-I-mediated Erk phosphorylation was observed in RACK1-overexpressing H9c2 cells. Interestingly, contrary to observations in transformed cells, RACK1 was not observed to interact with the IGF-IR in H9c2 cells. Also in contrast to observations in transformed cells, IGF-I promoted recruitment of Src to RACK1 as well as recruitment of PKCalpha, and PKCepsilon to RACK1. Overall, the data indicate that in H9c2 cells RACK1 can influence cell size, cell survival, adhesion, migration, but its responses to IGF-I are independent of an association with the IGF-IR. Thus, the composition of the RACK1 scaffolding complex and its effects on IGF-I signalling may be different in transformed and non-transformed cells.
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Affiliation(s)
- Helen C O'Donovan
- Cell Biology Laboratory, Department of Biochemistry, BioSciences Institute, National University of Ireland, Cork, Ireland
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22
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Zakrzewicz A, Hecker M, Marsh LM, Kwapiszewska G, Nejman B, Long L, Seeger W, Schermuly RT, Morrell NW, Morty RE, Eickelberg O. Receptor for Activated C-Kinase 1, a Novel Interaction Partner of Type II Bone Morphogenetic Protein Receptor, Regulates Smooth Muscle Cell Proliferation in Pulmonary Arterial Hypertension. Circulation 2007; 115:2957-68. [PMID: 17515463 DOI: 10.1161/circulationaha.106.670026] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is characterized by selective elevation of pulmonary arterial pressure. The pathological hallmark of PAH is the narrowing of pulmonary arterioles secondary to endothelial cell dysfunction and smooth muscle cell proliferation. Heterozygous mutations in BMPR2, encoding the type II bone morphogenetic protein receptor (BMPRII), were identified in PAH, suggesting that alterations to BMPRII function are involved in disease onset and/or progression. METHODS AND RESULTS We identified the receptor for activated C-kinase (RACK1) as a novel interaction partner of BMPRII by yeast 2-hybrid analyses using the kinase domain of BMPRII as a bait. Glutathione-S-transferase pull-down and coimmunoprecipitation confirmed the interaction of RACK1 with BMPRII in vitro and in vivo. RACK1-BMPRII interaction was reduced when kinase domain mutations occurring in patients with PAH were introduced to BMPRII. Immunohistochemistry of lung sections from PAH and control patients and immunofluorescence analysis of primary pulmonary arterial smooth muscle cells demonstrated colocalization of BMPRII and RACK1 in vivo. Quantitative reverse-transcription polymerase chain reaction and Western blot analysis showed significant downregulation of RACK1 expression in the rat model of monocrotaline-induced PAH but not in pulmonary arterial smooth muscle cells from PAH patients. Abrogation of RACK1 expression in pulmonary arterial smooth muscle cells led to decreased Smad1 phosphorylation and increased proliferation, whereas overexpression of RACK1 led to increased Smad1 phosphorylation and decreased proliferation. CONCLUSIONS RACK1, a novel interaction partner of BMPRII, constitutes a new negative regulator of pulmonary arterial smooth muscle cell proliferation, suggesting a potential role for RACK1 in the pathogenesis of PAH.
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Affiliation(s)
- Anna Zakrzewicz
- University of Giessen Lung Center, Department of Medicine II, Justus Liebig University Giessen, D-35392 Giessen, Germany
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Rothberg KG, Burdette DL, Pfannstiel J, Jetton N, Singh R, Ruben L. The RACK1 homologue from Trypanosoma brucei is required for the onset and progression of cytokinesis. J Biol Chem 2006; 281:9781-90. [PMID: 16469736 PMCID: PMC1997280 DOI: 10.1074/jbc.m600133200] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The receptor for activated C kinase 1 (RACK1) is a conserved scaffold protein that helps regulate a range of cell activities including cell growth, shape, and protein translation. We report that a homologue of RACK1 is required for cytokinesis in pathogenic Trypanosoma brucei. The protein, referred to as TRACK, is comprised of WD repeat elements and can complement cpc2 null mutants of Schizosaccharomyces pombe. TRACK is expressed throughout the trypanosome life cycle and is distributed predominantly in a perinuclear region and the cytoplasm but not along the endoplasmic reticulum, mitochondrion, or cleavage furrow of dividing cells. When tetracycline-inducible RNA interference (RNAi) is used to deplete the cellular content of TRACK, the cells remain metabolically active, but growth is inhibited. In bloodstream forms, growth arrest is due to a delay in the onset of cytokinesis. By contrast, procyclic forms are able to initiate cytokinesis in the absence of TRACK but arrest midway through cell cleavage. The RNAi cells undergo multiple rounds of partial cytokinesis and accumulate nuclei and cytoplasmic extensions with attached flagella. The TRACK RNAi construct is also inducible within infected mice. Under these conditions parasites are eliminated from peripheral blood within 3 days post-infection. Taken as a whole, these data indicate that trypanosomes utilize a RACK1 homologue to regulate the final stages of mitosis. Moreover, disrupting the interaction between TRACK and its partners might be targeted in the design of novel therapies.
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Affiliation(s)
- Karen G Rothberg
- Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275, USA
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24
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Sklan EH, Podoly E, Soreq H. RACK1 has the nerve to act: structure meets function in the nervous system. Prog Neurobiol 2006; 78:117-34. [PMID: 16457939 DOI: 10.1016/j.pneurobio.2005.12.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2005] [Revised: 11/20/2005] [Accepted: 12/07/2005] [Indexed: 11/26/2022]
Abstract
The receptor for activated protein kinase C 1 (RACK1) is an intracellular adaptor protein. Accumulating evidence attributes to this member of the tryptophan-aspartate (WD) repeat family the role of regulating several major nervous system pathways. Structurally, RACK1 is a seven-bladed-beta-propeller, interacting with diverse proteins having distinct structural folds. When bound to the IP3 receptor, RACK1 regulates intracellular Ca2+ levels, potentially contributing to processes such as learning, memory and synaptic plasticity. By binding to the NMDA receptor, it dictates neuronal excitation and sensitivity to ethanol. When bound to the stress-induced acetylcholinesterase variant AChE-R, RACK1 is implicated in stress responses and behavior, compatible with reports of RACK1 modulations in brain ageing and in various neurodegenerative diseases. This review sheds new light on both the virtues and the variety of neuronal RACK1 interactions and their physiological consequences.
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Affiliation(s)
- Ella H Sklan
- The Department of Biological Chemistry, The Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Cejas PJ, Carlson LM, Kolonias D, Zhang J, Lindner I, Billadeau DD, Boise LH, Lee KP. Regulation of RelB expression during the initiation of dendritic cell differentiation. Mol Cell Biol 2005; 25:7900-16. [PMID: 16107733 PMCID: PMC1190284 DOI: 10.1128/mcb.25.17.7900-7916.2005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The transcription factor RelB is required for proper development and function of dendritic cells (DCs), and its expression is upregulated early during differentiation from a variety of progenitors. We explored this mechanism of upregulation in the KG1 cell line model of a DC progenitor and in the differentiation-resistant KG1a subline. RelB expression is relatively higher in untreated KG1a cells but is upregulated only during differentiation of KG1 by an early enhancement of transcriptional elongation, followed by an increase in transcription initiation. Restoration of protein kinase CbetaII (PKCbetaII) expression in KG1a cells allows them to differentiate into DCs. We show that PKCbetaII also downregulated constitutive expression of NF-kappaB in KG1a-transfected cells and restores the upregulation of RelB during differentiation by increased transcriptional initiation and elongation. The two mechanisms are independent and sensitive to PKC signaling levels. Conversely, RelB upregulation was inhibited in primary human monocytes where PKCbetaII expression was knocked down by small interfering RNA targeting. Altogether, the data show that RelB expression during DC differentiation is controlled by PKCbetaII-mediated regulation of transcriptional initiation and elongation.
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Affiliation(s)
- Pedro J Cejas
- University of Miami School of Medicine, Department of Microbiology and Immunology, FL 33136, USA
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26
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Cejas PJ, Carlson LM, Zhang J, Padmanabhan S, Kolonias D, Lindner I, Haley S, Boise LH, Lee KP. Protein kinase C betaII plays an essential role in dendritic cell differentiation and autoregulates its own expression. J Biol Chem 2005; 280:28412-23. [PMID: 15917249 DOI: 10.1074/jbc.m500345200] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Dendritic cells (DC) arise from a diverse group of hematopoietic progenitors and have marked phenotypic and functional heterogeneity. The signal transduction pathways that regulate the ability of progenitors to undergo DC differentiation, as well as the specific characteristics of the resulting DC, are only beginning to be characterized. We have found previously that activation of protein kinase C (PKC) by cytokines or phorbol esters drives normal human CD34(+) hematopoietic progenitors and myeloid leukemic blasts (KG1, K562 cell lines, and primary patient blasts) to differentiate into DC. We now report that PKC activation is also required for cytokine-driven DC differentiation from monocytes. Of the cPKC isoforms, only PKC-betaII was consistently activated by DC differentiation-inducing stimuli in normal and leukemic progenitors. Transfection of PKC-betaII into the differentiation-resistant KG1a subline restored the ability to undergo DC differentiation in a signal strength-dependent fashion as follows: 1) by development of characteristic morphology; 2) the up-regulation of DC surface markers; 3) the induction of expression of the NFkappaB family member Rel B; and 4) the potent ability to stimulate allo-T cells. Most unexpectedly, the restoration of PKC-betaII signaling in KG1a was not directly due to overexpression of the transfected classical PKC (alpha, betaII, or gamma) but rather through induction of endogenous PKC-beta gene expression by the transfected classical PKC. The mechanism of this positive autoregulation involves up-regulation of PKC-beta promoter activity by constitutive PKC signaling. These findings indicate that the regulation of PKC-betaII expression and signaling play critical roles in mediating progenitor to DC differentiation.
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Affiliation(s)
- Pedro J Cejas
- Department of Microbiology and Immunology and Sylvester Comprehensive Cancer Center, University of Miami School of Medicine, Miami, Florida 33156, USA
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Gerbasi VR, Weaver CM, Hill S, Friedman DB, Link AJ. Yeast Asc1p and mammalian RACK1 are functionally orthologous core 40S ribosomal proteins that repress gene expression. Mol Cell Biol 2004; 24:8276-87. [PMID: 15340087 PMCID: PMC515043 DOI: 10.1128/mcb.24.18.8276-8287.2004] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Translation of mRNA into protein is a fundamental step in eukaryotic gene expression requiring the large (60S) and small (40S) ribosome subunits and associated proteins. By modern proteomic approaches, we previously identified a novel 40S-associated protein named Asc1p in budding yeast and RACK1 in mammals. The goals of this study were to establish Asc1p or RACK1 as a core conserved eukaryotic ribosomal protein and to determine the role of Asc1p or RACK1 in translational control. We provide biochemical, evolutionary, genetic, and functional evidence showing that Asc1p or RACK1 is indeed a conserved core component of the eukaryotic ribosome. We also show that purified Asc1p-deficient ribosomes have increased translational activity compared to that of wild-type yeast ribosomes. Further, we demonstrate that asc1Delta null strains have increased levels of specific proteins in vivo and that this molecular phenotype is complemented by either Asc1p or RACK1. Our data suggest that one of Asc1p's or RACK1's functions is to repress gene expression.
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Affiliation(s)
- Vincent R Gerbasi
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, 1161 21st Ave. South, Nashville, TN 37232-2363, USA
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28
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Seddas P, Boissinot S, Strub JM, Van Dorsselaer A, Van Regenmortel MHV, Pattus F. Rack-1, GAPDH3, and actin: proteins of Myzus persicae potentially involved in the transcytosis of beet western yellows virus particles in the aphid. Virology 2004; 325:399-412. [PMID: 15246278 DOI: 10.1016/j.virol.2004.05.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Revised: 04/09/2004] [Accepted: 05/11/2004] [Indexed: 10/26/2022]
Abstract
Beet western yellows virus (BWYV) is a Polerovirus that relies on the aphid Myzus persicae for its transmission, in a persistent-circulative mode. To be transmitted, the virus must cross the midgut and the accessory salivary glands (ASG) epithelial barriers in a transcytosis mechanism where vector receptors interact with virions. In this paper, we report in vitro interaction experiments between BWYV and aphid components. Using the M. persicae clone from Colmar, we showed that a set of aphid polypeptides, separated by SDS-PAGE or 2D electrophoresis (2DE), can bind in vitro to purified wild type or mutant particles. Using subcellular fractionation, we showed that the 65-kDa polypeptide identified as symbionin is a soluble protein whereas the other polypeptides seem to be associated more or less strongly to the membrane. We hypothesize that three polypeptides, identified by mass spectrometry as Rack-1, GAPDH3, and actin, may be involved in the epithelial transcytosis of virus particles in the aphid vector.
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Affiliation(s)
- Pascale Seddas
- Unité de Recherche Biologie des Interactions Virus/vecteurs, Institut National de la Recherche Agronomique, 68021 Colmar cedex, France.
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29
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Tian Q, Stepaniants SB, Mao M, Weng L, Feetham MC, Doyle MJ, Yi EC, Dai H, Thorsson V, Eng J, Goodlett D, Berger JP, Gunter B, Linseley PS, Stoughton RB, Aebersold R, Collins SJ, Hanlon WA, Hood LE. Integrated genomic and proteomic analyses of gene expression in Mammalian cells. Mol Cell Proteomics 2004; 3:960-9. [PMID: 15238602 DOI: 10.1074/mcp.m400055-mcp200] [Citation(s) in RCA: 601] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Using DNA microarrays together with quantitative proteomic techniques (ICAT reagents, two-dimensional DIGE, and MS), we evaluated the correlation of mRNA and protein levels in two hematopoietic cell lines representing distinct stages of myeloid differentiation, as well as in the livers of mice treated for different periods of time with three different peroxisome proliferative activated receptor agonists. We observe that the differential expression of mRNA (up or down) can capture at most 40% of the variation of protein expression. Although the overall pattern of protein expression is similar to that of mRNA expression, the incongruent expression between mRNAs and proteins emphasize the importance of posttranscriptional regulatory mechanisms in cellular development or perturbation that can be unveiled only through integrated analyses of both proteins and mRNAs.
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Affiliation(s)
- Qiang Tian
- The Institute for Systems Biology, 1441 North 34th Street, Seattle, WA 98103, USA.
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30
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Thornton C, Tang KC, Phamluong K, Luong K, Vagts A, Nikanjam D, Yaka R, Ron D. Spatial and temporal regulation of RACK1 function and N-methyl-D-aspartate receptor activity through WD40 motif-mediated dimerization. J Biol Chem 2004; 279:31357-64. [PMID: 15140893 DOI: 10.1074/jbc.m402316200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Efficient signaling requires accurate spatial and temporal compartmentalization of proteins. RACK1 is a scaffolding protein that fulfils this role through interaction of binding partners with one of its seven WD40 domains. We recently identified the kinase Fyn and the NR2B subunit of the N-methyl-D-Aspartate receptor (NMDAR) as binding partners of RACK1. Scaffolding of Fyn near its substrate NR2B by RACK1 inhibits Fyn phosphorylation of NR2B and thereby negatively regulates channel function. We found that Fyn and NR2B share the same binding site on RACK1; however, their binding to RACK1 is not mutually exclusive (Yaka, R., Thornton, C., Vagts, A. J., Phamluong, K., Bonci, A., and Ron, D. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 5710-5715). We therefore tested the hypothesis that RACK1 forms a homodimer that allows the simultaneous binding of Fyn and NR2B. We found that RACK1 binds to itself both in vitro and in the brain. Deletion analyses identified a RACK1-RACK1 dimer-binding site within the 4th WD40 repeat, and application of the 4th WD40 repeat or a peptide derivative to hippocampal slices inhibited NMDAR activity. We further found that in hippocampal slices, both RACK1 and NR2B associated with another WD40 protein, the beta-subunit of G protein (Gbeta), previously shown to heterodimerize with RACK1 in vitro (Dell, E. J., Connor, J., Chen, S., Stebbins, E. G., Skiba, N. P., Mochly-Rosen, D., and Hamm, H. E. (2002) J. Biol. Chem. 277, 49888-49895). However, activation of the pituitary adenylate cyclase polypeptide (1-38) G protein-coupled receptor, previously found to induce the dissociation of RACK1 from the NMDAR complex (Yaka, R., He, D. Y., Phamluong, K., and Ron, D. (2003) J. Biol. Chem. 278, 9630-9638), attenuated the association of Gbeta with RACK1 and NR2B. Based on these results, we propose that WD40-mediated homo- and heterodimerization of RACK1 mediate the formation of a transient signaling complex that includes the NMDAR, a G protein and Fyn.
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Affiliation(s)
- Claire Thornton
- Ernest Gallo Research Center, Emeryville, California 94608, USA
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31
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Severino A, Baldi A, Cottone G, Han M, Sang N, Giordano A, Mileo AM, Paggi MG, De Luca A. RACK1 is a functional target of the E1A oncoprotein. J Cell Physiol 2004; 199:134-9. [PMID: 14978742 DOI: 10.1002/jcp.10448] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The adenoviral E1A proteins have been implicated in promotion of proliferation and transformation, inhibition of differentiation, induction of apoptosis, regulation of transcription, and suppression of tumor growth. The ability of E1A to override the fundamental controls of host cells is based on its ability to physically interact with several cellular proteins. We recently characterized RACK1 as a new E1A-interacting protein. In this report, we show that the extreme N-terminal region of E1A, spanning from aminoacids 1-36, and the conserved WD regions of RACK1 are responsible for this interaction. We also demonstrate that E1A and RACK1 colocalize at the perinuclear membrane in the cells. Furthermore, we provide evidence that E1A is able to antagonize the inhibitory effects of RACK1 on Src activity. These results suggest that RACK1 signaling pathway may be a functional target of E1A, contributing to E1A oncogenic effect in the host cells.
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Affiliation(s)
- Anna Severino
- Laboratory C, Department for the Development of Therapeutic Programs, Center for Experimental Research, Regina Elena Cancer Institute, Rome, Italy
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32
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Nery FC, Passos DO, Garcia VS, Kobarg J. Ki-1/57 interacts with RACK1 and is a substrate for the phosphorylation by phorbol 12-myristate 13-acetate-activated protein kinase C. J Biol Chem 2003; 279:11444-55. [PMID: 14699138 DOI: 10.1074/jbc.m306672200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Ki-1/57, the 57-kDa human protein antigen recognized by the CD30 antibody Ki-1, is a cytoplasmic and nuclear protein that is phosphorylated on serine and threonine residues. When isolated from the Hodgkin's lymphoma analogous cell line L540 Ki-1/57 co-immunoprecipitated with a Thr/Ser protein kinase activity. It has been also found to interact with hyaluronic acid and has therefore been termed intracellular IHABP4 (hyaluronan-binding protein 4). Recent studies demonstrated, however, that Ki-1/57 engages in specific interaction with the chromo-helicase-DNA-binding domain protein 3, a nuclear protein involved in chromatin remodeling and transcription regulation. We used the yeast two-hybrid system to find proteins interacting with Ki-1/57 and identified the adaptor protein RACK1 (receptor of activated kinase 1). Next, we confirmed this interaction in vitro and in vivo, performed detailed mapping studies of the interaction sites of Ki-1/57 and RACK-1, and demonstrated that Ki-1/57 also co-precipitates with protein kinase C (PKC) when isolated from phorbol 12-myristate 13-acetate (PMA)-activated L540 tumor cells and is a substrate for PKC phosphorylation in vitro and in vivo. Interestingly, the interaction of Ki-1/57 with RACK1 is abolished upon activation of L540 cells with PMA, which results in the phosphorylation of Ki-1/57 and its exit from the nucleus. Taken together, our data suggest that Ki-1/57 forms a stable complex with RACK-1 in unstimulated cells and upon PMA stimulation gets phosphorylated on threonine residues located at its extreme C terminus. These events associate Ki-1/57 with the RACK1/PKC pathway and may be important for the regulation of its cellular functions.
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Affiliation(s)
- Flávia C Nery
- Centro de Biologia Molecular Estrutural, Laboratório Nacional de Luz Síncrotron, Rua Giuseppe Máximo Scolfaro 10.000, C.P. 6192, 13084-971 Campinas, SP, Brasil
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33
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Shor B, Calaycay J, Rushbrook J, McLeod M. Cpc2/RACK1 is a ribosome-associated protein that promotes efficient translation in Schizosaccharomyces pombe. J Biol Chem 2003; 278:49119-28. [PMID: 12972434 DOI: 10.1074/jbc.m303968200] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cpc2/RACK1 is a highly conserved WD domain protein found in all eucaryotes. Cpc2/RACK1 functions on mammalian signal transduction pathways most notably as an adaptor protein for the betaII protein kinase C isozyme. In single cell eucaryotes, Cpc2/RACK1 regulates growth, differentiation, and entry into G0 stationary phase. The exact biochemical function of Cpc2/RACK1 is unknown. Here, we provide evidence that Cpc2 is associated with the ribosome. Using immunoaffinity purification, we isolated ribosomal proteins in association with Cpc2/RACK1. Polysome and ribosomal subunit analysis using velocity gradient centrifugation of cell lysates demonstrated that Cpc2 co-sediments with the 40 S ribosomal subunit and with polysomes. Conditions known to disrupt ribosome structure alter sedimentation of the ribosome and of Cpc2/RACK1 coordinately. Loss of cpc2 does not dramatically alter the rate of cellular protein synthesis but causes a decrease in the steady state level of numerous proteins, some of which regulate methionine metabolism. Whereas real time PCR analysis demonstrated that transcriptional mechanisms are responsible for down-regulation of some of these proteins, one protein, ribosomal protein L25, is probably regulated at the level of translation.
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Affiliation(s)
- Boris Shor
- Morse Institute for Molecular Genetics, Department of Microbiology and Immunology, State University of New York Downstate Medical Center, Brookyln, New York 1120-2098, USA
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34
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Ahmed FE. Colon cancer: prevalence, screening, gene expression and mutation, and risk factors and assessment. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2003; 21:65-131. [PMID: 15845222 DOI: 10.1081/gnc-120026233] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Colon cancer detection at an early stage and identifying susceptible individuals can result in reduced mortality from this prevalent cancer. Genetic events leading to the development of this cancer involve a multistage progression of adenoma polyps to invasive metastatic carcinomas. Currently, there is no satisfactory screening method that is highly specific, sensitive, or reliable. Dietary patterns associated with the greatest increase in colon cancer risk are the ones that typify a diet rich in fat and calories, and low in vegetable, fruits, and fibers. Genetic susceptibility to environmental carcinogenesis must be factored into the risk assessment for this cancer. Many genes have been shown to be associated with increased expression and mutations in colorectal cancer patients. These genes have been reviewed; it is hoped that by carefully selecting a number of them, a molecular approach that is suitable for arriving at a tumorigenic expression index is developed, which will reliably detect this cancer at an early stage (i.e., before it metastasizes), especially in exfoliated samples (e.g., stool and blood), so that appropriate intervention strategies can be implemented. Illustrated herein is the utility of employing real-time reverse transcriptase polymerase chain reaction (RT-PCR) to quantitatively measure gene expression, and develop an index that is specific for this cancer, which if perfected may result in a reliable and sensitive screening technique for colorectal cancer detection.
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Affiliation(s)
- Farid E Ahmed
- Department of Radiation Oncology, Leo W. Jenkins Cancer Center, The Brody School of Medicine, East Carolina University, Greenville, North Carolina 27858, USA.
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35
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Usacheva A, Tian X, Sandoval R, Salvi D, Levy D, Colamonici OR. The WD motif-containing protein RACK-1 functions as a scaffold protein within the type I IFN receptor-signaling complex. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:2989-94. [PMID: 12960323 DOI: 10.4049/jimmunol.171.6.2989] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The WD repeat-containing protein receptor for activated protein kinase C (RACK)-1 has been linked to a variety of signaling systems including protein kinase C, growth factors, and IFNs. In the IFN system, RACK-1 functions as an adaptor recruiting the transcription factor STAT1 to the receptor complex. However, RACK-1 should play a broader role in type I IFN signaling because mutation of the RACK-1 binding site in the IFN-alpha receptor 2/beta subunit of the type I IFN receptor abrogates not only STAT1, but also STAT2, activation. In this study, we demonstrate that RACK-1 serves as a scaffold protein for a multiprotein complex that includes the IFN-alpha receptor 2/beta-chain of the receptor, STAT1, Janus kinase 1, and tyrosine kinase 2. In vitro data further suggest that within this complex tyrosine kinase 2 is the tyrosine kinase responsible for the phosphorylation of STAT1. Finally, we provide evidence that RACK-1 may also serve as a scaffold protein in other cytokine systems such as IL-2, IL-4, and erythropoietin.
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Affiliation(s)
- Anna Usacheva
- Department of Pharmacology, University of Illinois, Chicago, IL 60612, USA
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36
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Bjørndal B, Trave G, Hageberg I, Lillehaug JR, Raae AJ. Expression and purification of receptor for activated C-kinase 1 (RACK1). Protein Expr Purif 2003; 31:47-55. [PMID: 12963340 DOI: 10.1016/s1046-5928(03)00135-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Receptor for activated C-kinase (RACK1) binds to protein kinase C and functions as an anchor for several other cellular components. Most in vitro studies of RACK1 have been carried out with RACK1 fused to a soluble fusion protein partner, such as GST or MBP. Here, we show that fusion complexes may exist as large soluble aggregates and thereby lead to false conclusions about the biological activity of RACK1. We developed a purification procedure that gave soluble monodisperse molecules of the protein. The RACK1 gene was cloned and expressed in a pMAL vector. After purification of the resulting MBP-RACK1 fusion protein, RACK1 was excised from MBP by thrombin, rendering RACK1 in a soluble monodisperse form as monitored by fluorimetric static light scattering, gel filtration, and ultracentrifugation. Circular dichroism analysis revealed that RACK1 was properly folded with a T(m) of approximately 62 degrees C and contained the predicted portions of secondary structures. The biological activity of the purified protein was verified by binding to activated protein kinase C. The production of soluble, high-purity RACK1 will allow structural studies and functional in vitro studies to identify interacting partners to this important scaffold protein.
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Affiliation(s)
- Bodil Bjørndal
- Department of Molecular Biology, University of Bergen, HIB, P.O. Box 7800, 5020, Bergen, Norway
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37
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Huang CF, Fan JH, Chuang NN. Farnesyl pyrophosphate promotes and is essential for the binding of RACK1 with beta-tubulin. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, COMPARATIVE EXPERIMENTAL BIOLOGY 2003; 298:119-27. [PMID: 12884273 DOI: 10.1002/jez.a.10277] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Receptors for activated C kinase (RACKs) are a group of protein kinase C (PKC) binding proteins that have been shown to be crucial in the translocation and subsequent functioning of PKC on activation. RACK1 isolated from BALB/3T3 cells transformed with S-ras(Q61K) exhibits receptor activity for PKCgamma as competent as that of RACK1 from BALB/3T3 cells without transformation. However, the ability of RACK1 from transformed cells to bind with beta-tubulin peptide specific for Taxol (PEPtaxol) is defective. Interestingly, when farnesyl pyrophosphate was added at the submicrogram level, the association between RACK1 and PEPtaxol was enhanced significantly in a dosage-dependent manner. A parallel finding for the enhanced effect of farnesyl pyrophosphate on tubulin binding was established with mice RACK1 expressed in vitro. On the other hand, geranylgeranyl pyrophosphate, and retinoic acid failed to modulate the binding between RACK1 and tubulin. The dissociation of RACK1 and tubulin was not effective at damaging the binding between RACK1 and membrane receptor integrin beta1 in transformed cells. These findings indicate that depletion of farnesyl pyrophosphate provides a mechanism to seal PKC signaling on the membrane with immobile RACK1 and to divert cells to aberrant growth, such as transformation.
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Affiliation(s)
- Chein-Fuang Huang
- Division of Biochemistry and Molecular Science, Institute of Zoology, Academia Sinica, Nankang 11529, Taipei, Taiwan
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38
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Ozaki T, Watanabe KI, Nakagawa T, Miyazaki K, Takahashi M, Nakagawara A. Function of p73, not of p53, is inhibited by the physical interaction with RACK1 and its inhibitory effect is counteracted by pRB. Oncogene 2003; 22:3231-42. [PMID: 12761493 DOI: 10.1038/sj.onc.1206382] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The newly identified p53-related gene, p73, encodes a nuclear transcription factor. Unlike p53, p73 has various isoforms with different NH(2)- and COOH-terminal tails. p73alpha with the longest COOH-terminal extension is most abundantly expressed in many tissues and cells among those splicing isoforms of p73 and the COOH-terminal region appears to have an autoregulatory function. To isolate and characterize the cellular protein(s) that interacts with the unique COOH-terminal region of p73alpha, we employed a yeast two-hybrid screen with a human fetal brain and 293 cell cDNA libraries. We identified the receptor for activated C kinase (RACK1) as a new member of p73alpha-binding proteins. The interaction was confirmed by coimmunoprecipitation experiments, whereas RACK1 did not interact with p53 or p73beta. Ectopic overexpression of RACK1 in SAOS-2 cells reduced the p73alpha-mediated transcription from the p53/p73-responsive promoters, and inhibited the p73alpha-dependent apoptosis. On the other hand, the p53-dependent transcriptional activation as well as apoptosis was unaffected in the presence of RACK1. Furthermore, we found that pRB physically bound to RACK1, and repressed the RACK1-dependent inhibition of p73alpha. Taken together, our observations suggest that pRB diminishes the RACK1-mediated inhibition of p73alpha activity through the interaction with RACK1.
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Affiliation(s)
- Toshinori Ozaki
- Division of Biochemistry, Chiba Cancer Center Research Institute, 666-2 Nitona, Chuoh-ku, Chiba 260-8717, Japan
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Cox EA, Bennin D, Doan AT, O'Toole T, Huttenlocher A. RACK1 regulates integrin-mediated adhesion, protrusion, and chemotactic cell migration via its Src-binding site. Mol Biol Cell 2003; 14:658-69. [PMID: 12589061 PMCID: PMC149999 DOI: 10.1091/mbc.e02-03-0142] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Mammalian cDNA expression cloning was used to identify novel regulators of integrin-mediated cell-substratum adhesions. Using a focal adhesion morphology screen, we identified a cDNA with homology to a receptor for activated protein kinase C (RACK1) that induced a loss of central focal adhesions and stress fibers in CHO-K1 cells. The identified cDNA was a C-terminal truncated form of RACK1 that had one of the putative protein kinase C binding sites but lacked the region proposed to bind the beta integrin cytoplasmic domain and the tyrosine kinase Src. To investigate the role of RACK1 during cell spreading and migration, we tagged RACK1, a C-terminal truncated RACK1 and a point mutant that does not bind Src (RACK Y246F) with green fluorescent protein and expressed them in CHO-K1 cells. We found that RACK1 regulates the organization of focal adhesions and that it localizes to a subset of nascent focal complexes in areas of protrusion that contain paxillin but not vinculin. We also found that RACK1 regulates cell protrusion and chemotactic migration through its Src binding site. Together, these findings suggest that RACK1 regulates adhesion, protrusion, and chemotactic migration through its interaction with Src.
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Affiliation(s)
- Elisabeth A Cox
- Departments of Pediatrics and Pharmacology, University of Wisconsin, Madison 53706, USA
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40
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Yokota SI, Saito H, Kubota T, Yokosawa N, Amano KI, Fujii N. Measles virus suppresses interferon-alpha signaling pathway: suppression of Jak1 phosphorylation and association of viral accessory proteins, C and V, with interferon-alpha receptor complex. Virology 2003; 306:135-46. [PMID: 12620806 DOI: 10.1016/s0042-6822(02)00026-0] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To establish infections, viruses use various strategies to suppress the host defense mechanism, such as interferon (IFN)-induced antiviral state. We found that cells infected with a wild strain of measles virus (MeV) displayed nearly complete suppression of IFN-alpha-induced antiviral state, but not IFN-gamma-induced state. This phenomenon is due to the suppression of IFN-alpha-inducible gene expression at a transcriptional level. In the IFN-alpha signal transduction pathway, Jak1 phosphorylation induced by IFN-alpha is dramatically suppressed in MeV-infected cells; however, phosphorylation induced by IFN-gamma is not. We performed immunoprecipitation experiments using antibodies against type 1 IFN receptor chain 1 (INFAR1) and antibody against RACK1, which is reported to be a scaffold protein interacting with type I IFN receptor chain 2 and STAT1. These experiments indicated that IFNAR1 forms a complex containing the MeV-accessory proteins C and V, RACK1, and STAT1 in MeV-infected cells but not in uninfected cells. Composition of this complex in the infected cells altered little by IFN-alpha treatment. These results indicate that MeV suppresses the IFN-alpha, but not IFN-gamma, signaling pathway by inhibition of Jak1 phosphorylation. Our data suggest that functional disorder of the type I IFN receptor complex is due to "freezing" of the receptor through its association with the C and/or V proteins of MeV.
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Affiliation(s)
- Shin-ichi Yokota
- Department of Microbiology, Sapporo Medical University School of Medicine, Chuo-ku, 060-8556, Sapporo, Japan
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41
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Dell EJ, Connor J, Chen S, Stebbins EG, Skiba NP, Mochly-Rosen D, Hamm HE. The betagamma subunit of heterotrimeric G proteins interacts with RACK1 and two other WD repeat proteins. J Biol Chem 2002; 277:49888-95. [PMID: 12359736 DOI: 10.1074/jbc.m202755200] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A yeast two-hybrid approach was used to discern possible new effectors for the betagamma subunit of heterotrimeric G proteins. Three of the clones isolated are structurally similar to Gbeta, each exhibiting the WD40 repeat motif. Two of these proteins, the receptor for activated C kinase 1 (RACK1) and the dynein intermediate chain, co-immunoprecipitate with Gbetagamma using an anti-Gbeta antibody. The third protein, AAH20044, has no known function; however, sequence analysis indicates that it is a WD40 repeat protein. Further investigation with RACK1 shows that it not only interacts with Gbeta(1)gamma(1) but also unexpectedly with the transducin heterotrimer Galpha(t)beta(1)gamma(1). Galpha(t) alone does not interact, but it must contribute to the interaction because the apparent EC(50) value of RACK1 for Galpha(t)beta(1)gamma(1) is 3-fold greater than that for Gbeta(1)gamma(1) (0.1 versus 0.3 microm). RACK1 is a scaffold that interacts with several proteins, among which are activated betaIIPKC and dynamin-1 (1). betaIIPKC and dynamin-1 compete with Gbeta(1)gamma(1) and Galpha(t)beta(1)gamma(1) for interaction with RACK1. These findings have several implications: 1) that WD40 repeat proteins may interact with each other; 2) that Gbetagamma interacts differently with RACK1 than with its other known effectors; and/or 3) that the G protein-RACK1 complex may constitute a signaling scaffold important for intracellular responses.
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Affiliation(s)
- Edward J Dell
- Institute for Neuroscience and Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Medical School, Chicago, Illinois 60613, USA
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42
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McCahill A, Warwicker J, Bolger GB, Houslay MD, Yarwood SJ. The RACK1 scaffold protein: a dynamic cog in cell response mechanisms. Mol Pharmacol 2002; 62:1261-73. [PMID: 12435793 DOI: 10.1124/mol.62.6.1261] [Citation(s) in RCA: 304] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Angela McCahill
- Molecular Pharmacology Group, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow, Scotland, UK
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Tcherkasowa AE, Adam-Klages S, Kruse ML, Wiegmann K, Mathieu S, Kolanus W, Krönke M, Adam D. Interaction with factor associated with neutral sphingomyelinase activation, a WD motif-containing protein, identifies receptor for activated C-kinase 1 as a novel component of the signaling pathways of the p55 TNF receptor. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:5161-70. [PMID: 12391233 DOI: 10.4049/jimmunol.169.9.5161] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Factor associated with neutral sphingomyelinase activation (FAN) represents a p55 TNFR (TNF-R55)-associated protein essential for the activation of neutral sphingomyelinase. By means of the yeast interaction trap system, we have identified the scaffolding protein receptor for activated C-kinase (RACK)1 as an interaction partner of FAN. Mapping studies in yeast revealed that RACK1 is recruited to the C-terminal WD-repeat region of FAN and binds to FAN through a domain located within WD repeats V to VII of RACK1. Our data indicate that binding of both proteins is not mediated by linear motifs but requires folding into a secondary structure, such as the multibladed propeller characteristic of WD-repeat proteins. The interaction of FAN and RACK1 was verified in vitro by glutathione S-transferase-based coprecipitation assays as well as in eukaryotic cells by coimmunoprecipitation experiments. Colocalization studies in transfected cells suggest that TNF-R55 forms a complex with FAN and that this complex recruits RACK1 to the plasma membrane. Furthermore, activation of N-SMase by TNF was strongly enhanced when RACK1, FAN, and a noncytotoxic TNF-R55 mutant were expressed concurrently, suggesting RACK1 as a modulator of N-SMase activation. Together, these findings implicate RACK1 as a novel component of the signaling pathways of TNF-R55.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Animals
- Antigens, CD/chemistry
- Antigens, CD/genetics
- Antigens, CD/physiology
- COS Cells
- Cell Line
- Enzyme Activation/genetics
- Enzyme Activation/immunology
- HeLa Cells
- Humans
- Intracellular Fluid/metabolism
- Intracellular Signaling Peptides and Proteins
- Jurkat Cells
- Molecular Sequence Data
- Peptide Fragments/chemistry
- Peptide Fragments/genetics
- Peptide Fragments/metabolism
- Precipitin Tests
- Protein Binding/genetics
- Protein Binding/immunology
- Protein Interaction Mapping/methods
- Protein Kinase C/chemistry
- Protein Kinase C/genetics
- Protein Kinase C/metabolism
- Proteins/chemistry
- Proteins/genetics
- Proteins/metabolism
- Receptors for Activated C Kinase
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Receptors, Tumor Necrosis Factor/chemistry
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Receptors, Tumor Necrosis Factor, Type I
- Repetitive Sequences, Amino Acid
- Signal Transduction/genetics
- Signal Transduction/immunology
- Sphingomyelin Phosphodiesterase/chemistry
- Sphingomyelin Phosphodiesterase/genetics
- Sphingomyelin Phosphodiesterase/metabolism
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Lee HS, Millward-Sadler SJ, Wright MO, Nuki G, Al-Jamal R, Salter DM. Activation of Integrin-RACK1/PKCalpha signalling in human articular chondrocyte mechanotransduction. Osteoarthritis Cartilage 2002; 10:890-7. [PMID: 12435334 DOI: 10.1053/joca.2002.0842] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The objective of this study was to examine PKC isozyme expression in human articular chondrocytes and assess roles for RACK1, a receptor for activated C kinase in the mechanotransduction process. METHODS Primary cultures of human articular chondrocytes and a human chondrocyte cell line were studied for expression of PKC isozymes and RACK1 by western blotting. Following mechanical stimulation of chondrocytes in vitro in the absence or presence of anti-integrin antibodies and RGD containing oligopeptides, subcellular localization of PKCalpha and association of RACK1 with PKCalpha and beta1 integrin was assessed. RESULTS Human articular chondrocytes express PKC isozymes alpha, gamma, delta, iota, and lambda. Following mechanical stimulation at 0.33Hz chondrocytes show a rapid, beta1 integrin dependent, translocation of PKCalpha to the cell membrane and increased association of RACK1 with PKCalpha and beta1 integrin. CONCLUSIONS RACK1 mediated translocation of activated PKCalpha to the cell membrane and modulation of integrin-associated signaling are likely to be important in regulation of downstream signaling cascades controlling chondrocyte responses to mechanical stimuli.
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Affiliation(s)
- H-S Lee
- Department of Pathology, Edinburgh University Medical School, UK
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Bolger GB, McCahill A, Yarwood SJ, Steele MR, Warwicker J, Houslay MD. Delineation of RAID1, the RACK1 interaction domain located within the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5. BMC BIOCHEMISTRY 2002; 3:24. [PMID: 12193273 PMCID: PMC126212 DOI: 10.1186/1471-2091-3-24] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2002] [Accepted: 08/23/2002] [Indexed: 11/10/2022]
Abstract
BACKGROUND The cyclic AMP specific phosphodiesterase, PDE4D5 interacts with the beta-propeller protein RACK1 to form a signaling scaffold complex in cells. Two-hybrid analysis of truncation and mutant constructs of the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5 were used to define a domain conferring interaction with the signaling scaffold protein, RACK1. RESULTS Truncation and mutagenesis approaches showed that the RACK1-interacting domain on PDE4D5 comprised a cluster of residues provided by Asn-22/Pro-23/Trp-24/Asn-26 together with a series of hydrophobic amino acids, namely Leu-29, Val-30, Leu-33, Leu-37 and Leu-38 in a 'Leu-Xaa-Xaa-Xaa-Leu' repeat. This was done by 2-hybrid analyses and then confirmed in biochemical pull down analyses using GST-RACK1 and mutant PDE4D5 forms expressed in COS cells. Mutation of Arg-34, to alanine, in PDE4D5 attenuated its interaction with RACK1 both in 2-hybrid screens and in pull down analyses. A 38-mer peptide, whose sequence reflected residues 12 through 49 of PDE4D5, bound to RACK1 with similar affinity to native PDE4D5 itself (Ka circa 6 nM). CONCLUSIONS The RACK1 Interaction Domain on PDE4D5, that we here call RAID1, is proposed to form an amphipathic helical structure that we suggest may interact with the C-terminal beta-propeller blades of RACK1 in a manner akin to the interaction of the helical G-gamma signal transducing protein with the beta-propeller protein, G-beta.
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Affiliation(s)
- Graeme B Bolger
- Veterans Affairs Medical Center, Huntsman Cancer Institute, Departments of Medicine (Division of Oncology) and Oncological Science, University of Utah Health Sciences Center, Salt Lake City, UT 84148 USA
- University of Alabama at Birmingham, Comprehensive Cancer Center, WTI 520, 1530 3rd Ave. S., Birmingham AL 35294-3300, USA
| | - Angela McCahill
- Molecular Pharmacology Group, Division of Biochemistry & Molecular Biology, Davidson Building, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Stephen J Yarwood
- Molecular Pharmacology Group, Division of Biochemistry & Molecular Biology, Davidson Building, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Michael R Steele
- Veterans Affairs Medical Center, Huntsman Cancer Institute, Departments of Medicine (Division of Oncology) and Oncological Science, University of Utah Health Sciences Center, Salt Lake City, UT 84148 USA
| | - Jim Warwicker
- Dept of Biomolecular Sciences, UMIST, Sackville Street, Manchester M60 1QD, UK
| | - Miles D Houslay
- Molecular Pharmacology Group, Division of Biochemistry & Molecular Biology, Davidson Building, Institute of Biomedical & Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
- Dept of Biomolecular Sciences, UMIST, Sackville Street, Manchester M60 1QD, UK
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He DY, Vagts AJ, Yaka R, Ron D. Ethanol induces gene expression via nuclear compartmentalization of receptor for activated C kinase 1. Mol Pharmacol 2002; 62:272-80. [PMID: 12130678 DOI: 10.1124/mol.62.2.272] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Scaffolding proteins such as receptor for activated C kinase (RACK) 1 are involved in the targeting of signaling proteins and play an important role in the regulation of signal transduction cascades. Recently, we found that in cultured cells and in vivo, acute ethanol exposure induces the nuclear compartmentalization of RACK1. To elucidate a physiological role for nuclear RACK1, the Tat protein transduction system was used to transduce RACK1 and RACK1-derived fragments into C6 glioma cells. We found that nuclear RACK1 is mediating the induction of the immediate early gene c-fos expression induced by ethanol. First, transduction of full-length RACK1 (Tat-RACK1) resulted in the induction of c-fos expression and enhancement of ethanol activities. Second, we determined that the C terminus of RACK1 (Tat-RACK1DeltaN) is mediating transcription. Third, we identified a dominant negative fragment of RACK1 that inhibited the nuclear compartmentalization of endogenous RACK1 and inhibited ethanol-induction of c-fos mRNA and protein expression. Last, acute exposure to ethanol or transduction of full-length Tat-RACK1 resulted in an increase in mRNA levels of an activator protein 1 site-containing gene, PAC1 (pituitary adenylate cyclase-activating polypeptide receptor type I), suggesting that nuclear RACK1 is involved in the regulation of the expression of genes that are altered upon acute ethanol treatment. These results may therefore have important implications for the study of alcohol addiction.
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Affiliation(s)
- Dao-Yao He
- Ernest Gallo Research Center, Emeryville, California, USA
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Kiely PA, Sant A, O'Connor R. RACK1 is an insulin-like growth factor 1 (IGF-1) receptor-interacting protein that can regulate IGF-1-mediated Akt activation and protection from cell death. J Biol Chem 2002; 277:22581-9. [PMID: 11964397 DOI: 10.1074/jbc.m201758200] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The insulin receptor and insulin-like growth factor 1 receptor (IGF-1R), activated by their ligands, control metabolism, cell survival, and proliferation. Although the signaling pathways activated by these receptors are well characterized, regulation of their activity is poorly understood. To identify regulatory proteins we undertook a two-hybrid screen using the IGF-1R beta-chain as bait. This screen identified Receptor for Activated C Kinases (RACK1) as an IGF-1R-interacting protein. RACK1 also interacted with the IGF-1R in fibroblasts and MCF-7 cells and with endogenous insulin receptor in COS cells. Interaction with the IGF-1R did not require tyrosine kinase activity or receptor autophosphorylation but did require serine 1248 in the C terminus. Overexpression of RACK1 in either R+ fibroblasts or MCF-7 cells inhibited IGF-1-induced phosphorylation of Akt, whereas it enhanced phosphorylation of Erks and Jnks. Src, the p85 subunit of phosphatidylinositol 3-kinase, and SHP-2 were all associated with RACK1 in these cells. Interestingly, the proliferation of MCF-7 cells was enhanced by overexpression of RACK1, whereas IGF-1-mediated protection from etoposide killing was greatly reduced. Altogether the data indicate that RACK1 is an IGF-1R-interacting protein that can modulate receptor signaling and suggest that RACK1 has a particular role in regulating Akt activation and cell survival.
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Affiliation(s)
- Patrick A Kiely
- Cell Biology Laboratory, Department of Biochemistry and Bioscience Institute, National University of Ireland, Lee Maltings Cork, Ireland
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Liedtke CM, Yun CHC, Kyle N, Wang D. Protein kinase C epsilon-dependent regulation of cystic fibrosis transmembrane regulator involves binding to a receptor for activated C kinase (RACK1) and RACK1 binding to Na+/H+ exchange regulatory factor. J Biol Chem 2002; 277:22925-33. [PMID: 11956211 DOI: 10.1074/jbc.m201917200] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein kinase C (PKC) regulation of cystic fibrosis transmembrane regulator (CFTR) chloride function has been demonstrated in several cell lines, including Calu-3 cells that express native, wild-type CFTR. We demonstrated previously that PKC epsilon was required for cAMP-dependent CFTR function. The goal of this study was to determine whether PKC epsilon interacts directly with CFTR. Using overlay assay, immunoprecipitation, pulldown and binding assays, we show that PKC epsilon does not bind to CFTR, but does bind to a receptor for activated C kinase (RACK1), a 37-kDa scaffold protein, and that RACK1 binds to Na(+)/H(+) exchange regulatory factor (NHERF1), a binding partner of CFTR. In vitro binding assays demonstrate dose-dependent binding of PKC epsilon to RACK1 which is inhibited by an 8-amino acid peptide based on the sequence of the sixth Trp-Asp repeat in RACK1 or by an 8-amino acid sequence in the V1 region of PKC epsilon, epsilon V1-2. A 4-amino acid sequence INAL (70-73) expressed in CFTR shares 50% homology to the RACK1 inhibitory peptide, but it does not bind PKC epsilon. NHERF1 and RACK1 bind in a dose-dependent manner. Immunofluorescence and confocal microscopy of RACK1 and CFTR revealed colocalization of the proteins to the apical and lateral regions of Calu-3 cells. The results indicate the RACK1 binds PKC epsilon and NHERF1, thus serving as a scaffold protein to anchor the enzyme in proximity to CFTR.
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Affiliation(s)
- Carole M Liedtke
- Warren Alan Bernbaum, M.D. Center for Cystic Fibrosis Research, Department of Pediatrics, Rainbow Babies and Children Hospital and Case Western Reserve University, Cleveland, Ohio 44106-4948, USA.
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Besson A, Wilson TL, Yong VW. The anchoring protein RACK1 links protein kinase Cepsilon to integrin beta chains. Requirements for adhesion and motility. J Biol Chem 2002; 277:22073-84. [PMID: 11934885 DOI: 10.1074/jbc.m111644200] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Integrin affinity is modulated by intracellular signaling cascades, in a process known as "inside-out" signaling, leading to changes in cell adhesion and motility. Protein kinase C (PKC) plays a critical role in integrin-mediated events; however, the mechanism that links PKC to integrins remains unclear. Here, we report that PKCepsilon positively regulates integrin-dependent adhesion, spreading, and motility of human glioma cells. PKCepsilon activation was associated with increased focal adhesion and lamellipodia formation as well as clustering of select integrins, and it is required for phorbol 12-myristate 13-acetate-induced adhesion and motility. We provide novel evidence that the scaffolding protein RACK1 mediates the interaction between integrin beta chain and activated PKCepsilon. Both depletion of RACK1 by antisense strategy and overexpression of a truncated form of RACK1 which lacks the integrin binding region resulted in decreased PKCepsilon-induced adhesion and migration, suggesting that RACK1 links PKCepsilon to integrin beta chains. Altogether, these results provide a novel mechanistic link between PKC activation and integrin-mediated adhesion and motility.
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Affiliation(s)
- Arnaud Besson
- Department of Oncology, University of Calgary, Calgary, Alberta T2N 4N1, Canada
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Yaka R, Thornton C, Vagts AJ, Phamluong K, Bonci A, Ron D. NMDA receptor function is regulated by the inhibitory scaffolding protein, RACK1. Proc Natl Acad Sci U S A 2002; 99:5710-5. [PMID: 11943848 PMCID: PMC122836 DOI: 10.1073/pnas.062046299] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Phosphorylation regulates the function of ligand-gated ion channels such as the N-methyl d-aspartate (NMDA) receptor. Here we report a mechanism for modulation of the phosphorylation state and function of the NMDA receptor via an inhibitory scaffolding protein, RACK1. We found that RACK1 binds both the NR2B subunit of the NMDA receptor and the nonreceptor protein tyrosine kinase, Fyn. RACK1 inhibits Fyn phosphorylation of NR2B and decreases NMDA receptor-mediated currents in CA1 hippocampal slices. Peptides that disrupt the interactions between RACK1, NR2B, and Fyn induce phosphorylation and potentiate NMDA receptor-mediated currents. Therefore, RACK1 is a regulator of NMDA receptor function and may play a role in synaptic plasticity, addiction, learning, and memory.
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Affiliation(s)
- Rami Yaka
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, CA 94110-3518, USA
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