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Bertorello AM, Pires N, Igreja B, Pinho MJ, Vorkapic E, Wågsäter D, Wikström J, Behrendt M, Hamsten A, Eriksson P, Soares-da-Silva P, Brion L. Increased Arterial Blood Pressure and Vascular Remodeling in Mice Lacking Salt-Inducible Kinase 1 (SIK1). Circ Res 2015; 116:642-52. [DOI: 10.1161/circresaha.116.304529] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Rationale:
In human genetic studies a single nucleotide polymorphism within the salt-inducible kinase 1 (
SIK1
) gene was associated with hypertension. Lower SIK1 activity in vascular smooth muscle cells (VSMCs) leads to decreased sodium-potassium ATPase activity, which associates with increased vascular tone. Also, SIK1 participates in a negative feedback mechanism on the transforming growth factor-β1 signaling and downregulation of SIK1 induces the expression of extracellular matrix remodeling genes.
Objective:
To evaluate whether reduced expression/activity of SIK1 alone or in combination with elevated salt intake could modify the structure and function of the vasculature, leading to higher blood pressure.
Methods and Results:
SIK1 knockout (
sik1
−/−
) and wild-type (
sik1
+/+
) mice were challenged to a normal- or chronic high-salt intake (1% NaCl). Under normal-salt conditions, the
sik1
−/−
mice showed increased collagen deposition in the aorta but similar blood pressure compared with the
sik1
+/+
mice. During high-salt intake, the
sik1
+/+
mice exhibited an increase in SIK1 expression in the VSMCs layer of the aorta, whereas the
sik1
−/−
mice exhibited upregulated transforming growth factor-β1 signaling and increased expression of endothelin-1 and genes involved in VSMC contraction, higher systolic blood pressure, and signs of cardiac hypertrophy. In vitro knockdown of SIK1 induced upregulation of collagen in aortic adventitial fibroblasts and enhanced the expression of contractile markers and of endothelin-1 in VSMCs.
Conclusions:
Vascular SIK1 activation might represent a novel mechanism involved in the prevention of high blood pressure development triggered by high-salt intake through the modulation of the contractile phenotype of VSMCs via transforming growth factor-β1-signaling inhibition.
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Affiliation(s)
- Alejandro M. Bertorello
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Nuno Pires
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Bruno Igreja
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Maria João Pinho
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Emina Vorkapic
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Dick Wågsäter
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Johannes Wikström
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Margareta Behrendt
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Anders Hamsten
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Per Eriksson
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Patricio Soares-da-Silva
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
| | - Laura Brion
- From the Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Stockholm, Sweden (A.M.B., L.B.); Department of Research and Development, Bial-Portela & Cª, S.A., S. Mamede do Coronado, Portugal (N.P., B.I., P.S.-d.-S.); MedInUP-Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal (M.J.P., P.S.-d.-S.); Department of Medicine, Cardiovascular Genetics and Genomics, Karolinska Institutet, Stockholm, Sweden (E.V., D.W., A.H., P.E.); Division
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Popov S, Takemori H, Tokudome T, Mao Y, Otani K, Mochizuki N, Pires N, Pinho MJ, Franco-Cereceda A, Torielli L, Ferrandi M, Hamsten A, Soares-da-Silva P, Eriksson P, Bertorello AM, Brion L. Lack of salt-inducible kinase 2 (SIK2) prevents the development of cardiac hypertrophy in response to chronic high-salt intake. PLoS One 2014; 9:e95771. [PMID: 24752134 PMCID: PMC3994160 DOI: 10.1371/journal.pone.0095771] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/28/2014] [Indexed: 01/01/2023] Open
Abstract
Cardiac left ventricle hypertrophy (LVH) constitutes a major risk factor for heart failure. Although LVH is most commonly caused by chronic elevation in arterial blood pressure, reduction of blood pressure to normal levels does not always result in regression of LVH, suggesting that additional factors contribute to the development of this pathology. We tested whether genetic preconditions associated with the imbalance in sodium homeostasis could trigger the development of LVH without concomitant increases in blood pressure. The results showed that the presence of a hypertensive variant of α-adducin gene in Milan rats (before they become hypertensive) resulted in elevated expression of genes associated with LVH, and of salt-inducible kinase 2 (SIK2) in the left ventricle (LV). Moreover, the mRNA expression levels of SIK2, α-adducin, and several markers of cardiac hypertrophy were positively correlated in tissue biopsies obtained from human hearts. In addition, we found in cardiac myocytes that α-adducin regulates the expression of SIK2, which in turn mediates the effects of adducin on hypertrophy markers gene activation. Furthermore, evidence that SIK2 is critical for the development of LVH in response to chronic high salt diet (HS) was obtained in mice with ablation of the sik2 gene. Increases in the expression of genes associated with LVH, as well as increases in LV wall thickness upon HS, occurred only in sik2+/+ but not in sik2−/− mice. Thus LVH triggered by HS or the presence of a genetic variant of α-adducin requires SIK2 and is independent of elevated blood pressure. Inhibitors of SIK2 may constitute part of a novel therapeutic regimen aimed at prevention/regression of LVH.
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Affiliation(s)
- Sergej Popov
- Membrane Signaling Networks, Department of Medicine, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Hiroshi Takemori
- Laboratory of Cell Signaling and Metabolism, National Institute for Biomedical Innovation, Osaka, Japan
| | - Takeshi Tokudome
- Department of Biochemistry, National Cerebral and Cardiovascular Research Institute, Osaka, Japan
| | - Yuanjie Mao
- Department of Biochemistry, National Cerebral and Cardiovascular Research Institute, Osaka, Japan
| | - Kentaro Otani
- Regenerative Medicine and Tissue Engineering, National Cerebral and Cardiovascular Research Institute, Osaka, Japan
| | - Naoki Mochizuki
- Cell Biology, National Cerebral and Cardiovascular Research Institute, Osaka, Japan
| | - Nuno Pires
- BIAL - Portela & C, S.A., S. Mamede do Coronado, Portugal
| | - Maria João Pinho
- MedInUP - Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal
| | - Anders Franco-Cereceda
- Cardiothoracic Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Lucia Torielli
- Prassis Sigma-Tau Research Institute, Settimo Milanese, Milan, Italy
| | - Mara Ferrandi
- Prassis Sigma-Tau Research Institute, Settimo Milanese, Milan, Italy
| | - Anders Hamsten
- Cardiovascular Genetics and Genomics, Department of Medicine, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Patricio Soares-da-Silva
- BIAL - Portela & C, S.A., S. Mamede do Coronado, Portugal
- MedInUP - Center for Drug Discovery and Innovative Medicines, University of Porto, Porto, Portugal
| | - Per Eriksson
- Cardiovascular Genetics and Genomics, Department of Medicine, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Alejandro M. Bertorello
- Membrane Signaling Networks, Department of Medicine, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Laura Brion
- Membrane Signaling Networks, Department of Medicine, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
- * E-mail:
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3
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Pinho MJ, Ciscotto P, Bertorello AM, Soares-da-Silva P. Abstract 204: Sodium Sensing Network in Hypertension-Induced Cardiac Hypertrophy. Hypertension 2013. [DOI: 10.1161/hyp.62.suppl_1.a204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypertension is related to alterations of sodium homeostasis that promote abnormal accumulation of water in the intravascular compartment leading to blood pressure elevation. This process can been associated with increased heart mass resulting in cardiac hypertrophy. At cellular level, the concentration and active transport of Na+ is regulated by Na+,K+-ATPase enzyme (NK). In vitro studies have shown a correlation between high blood pressure, NK and SIK activities. Increases in intracellular Na+ are paralleled by elevations in intracellular Ca2+ via NCX1, leading to the activation of SIK1 by a Ca2+/calmodulin-dependent kinase. Activation of SIK1 results in the dephosphorylation of the NK α-subunit and an increase in its catalytic activity. Accordingly, the aim of the present study was to evaluate the cardiac Na+ sensing network changes associated with hypertension in aging hypertensive rats. Systolic and diastolic blood pressures, determined by the tail-cuff method, were significantly higher in 3, 13 and 21-month old SHR than in age-matched WKY. In the SHR, ageing was associated with increases in cardiac mass, gene expression of hypertrophic (α-skeletal muscle actin and β-myosin heavy chain) markers as well as inflammatory cytokine (IL-6). The decreased expression of heart SIK isoforms, SIK1 and SIK3, was associated with downregulation of transcription factors Snail2, Zeb1, MFAT5c and KLF4, in 13 and 21-month old SHR. Cardiac α2-isoform of NK was found to be decreased in 21 month old SHR. Whereas, NKα1, NHE3 and NCX1 showed no differences between age-matched SHR and WKY. Na+-dependent ASCT2 and Na+-independent LAT1 amino acid transporter transcript levels of were significantly higher in 21 month old SHR than in WKY. In the aged SHR, cardiac hypertrophy was associated with dysregulation of several elements of the intracellular Na+ sensing network. Downregulation of SIK1 and transcription factors is correlated with expression of NKα2, suggesting impaired sodium handling. It is proposed that, cardiac hypertrophy is not exclusively the consequence of mechanical stress but also of other factors associated with elevated blood pressure such as abnormal cell sodium homeostasis.Supported by grant PIC/IC/83204/2007.
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Affiliation(s)
- Maria J Pinho
- Dept of Pharmacology and Therapeutics, Faculty of Medicine, Univ Porto, Porto, Portugal
| | - Paula Ciscotto
- Membrane Signaling Networks, Atherosclerosis Rsch Unit, Dept of Medicine, Karolinska Institutet, Karolinska Univ Hosp-Solna, Stockholm, Sweden
| | - Alejandro M Bertorello
- Membrane Signaling Networks, Atherosclerosis Rsch Unit, Dept of Medicine, Karolinska Institutet, Karolinska Univ Hosp-Solna, Stockholm, Sweden
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Pinho MJ, Bertorello AM, Soares-da- Silva P. Abstract 325: Cardiac Hypertrophy in Spontaneous Hypertensive Rats (SHR) is Associated With Decreased Cardiac Expression of SIK1 and SIK3 Isoforms. Hypertension 2012. [DOI: 10.1161/hyp.60.suppl_1.a325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Numerous reports have highlighted the importance of protein kinases and transcription factors in cardiogenesis and cardiac hypertrophy. The salt-inducible kinase 1 (SIK1), a protein kinase encoded by the snf1lk gene, is involved in early cardiogenesis in mice. Genotype-phenotype association studies in three Swedish and one Japanese population-based cohorts suggested that 15Ser-SIK1 variant (15Gly-Ser change, T allele), bestow augmented SIK1 activity, was associated with lower blood pressure and decreases in left ventricular (LV) mass. The present study aims to determine the potential role of SIK1 as a mediator of cardiac hypertrophic signaling pathway and to evaluate age-related changes on the cardiac expression of several elements of the SIK network associated with hypertension, in Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). For this purpose, mRNA expression levels of skeletal actin (SkA), β-myosin heavy chain (β-MHC) and matrix metalloproteinase-9 (MMP-9) as markers for cardiac hypertrophy, SIK isoforms (SIK1, SIK2 and SIK3), and transcription factors (MEF2C, NFAT5c, KFL4, Snail1 and Snail2) were determined, using Taqman, in 13- , 52- and 91-week old SHR and their normotensive counterparts WKY. Systolic and diastolic blood pressures, determined by the tail-cuff method, were significantly higher in 3- , in 3- , 13- and 21-month old SHR than in age-matched WKY. In the SHR, increases in heart/tibia length ratio were associated to the overexpression of cardiac hypertrophic genes (SkA and β-MHC) and the underexpression of cardiac SIK3, at the age of 3- , 13- and 21-months. Ageing accompanied by a diminished mRNA expression of SIK1 in SHR, relative to WKY (both at 13- and 21-months of age). Whereas, Snail2, MFAT5c and KLF4 mRNA levels decreased with aged SHR, comparing to age-match WKY (both at 13- and 21-months of age). These results indicate that SIK1 and SIK3 isoforms might be upstream mediators of transcriptions factors implicated in the regulation of cardiac hypertrophic growth response. In conclusion, ageing in SHR is accompanied by cardiac alterations that include hypertrophy and dysfunction of the SIK signaling network. Supported by grant PIC/IC/83204/2007.
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Affiliation(s)
- Maria J Pinho
- Dept of Pharmacology and Therapeutics, Faculty of Medicine, Univ Porto, Porto, Portugal
| | - Alejandro M Bertorello
- Membrane Signaling Networks, Atherosclerosis Rsch Unit, Dept of Medicine, Karolinska Institutet, Karolinska Univ Hosp-Solna, Stockholm, Sweden
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Uebi T, Itoh Y, Hatano O, Kumagai A, Sanosaka M, Sasaki T, Sasagawa S, Doi J, Tatsumi K, Mitamura K, Morii E, Aozasa K, Kawamura T, Okumura M, Nakae J, Takikawa H, Fukusato T, Koura M, Nish M, Hamsten A, Silveira A, Bertorello AM, Kitagawa K, Nagaoka Y, Kawahara H, Tomonaga T, Naka T, Ikegawa S, Tsumaki N, Matsuda J, Takemori H. Involvement of SIK3 in glucose and lipid homeostasis in mice. PLoS One 2012; 7:e37803. [PMID: 22662228 PMCID: PMC3360605 DOI: 10.1371/journal.pone.0037803] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 04/24/2012] [Indexed: 01/20/2023] Open
Abstract
Salt-inducible kinase 3 (SIK3), an AMP-activated protein kinase-related kinase, is induced in the murine liver after the consumption of a diet rich in fat, sucrose, and cholesterol. To examine whether SIK3 can modulate glucose and lipid metabolism in the liver, we analyzed phenotypes of SIK3-deficent mice. Sik3(-/-) mice have a malnourished the phenotype (i.e., lipodystrophy, hypolipidemia, hypoglycemia, and hyper-insulin sensitivity) accompanied by cholestasis and cholelithiasis. The hypoglycemic and hyper-insulin-sensitive phenotypes may be due to reduced energy storage, which is represented by the low expression levels of mRNA for components of the fatty acid synthesis pathways in the liver. The biliary disorders in Sik3(-/-) mice are associated with the dysregulation of gene expression programs that respond to nutritional stresses and are probably regulated by nuclear receptors. Retinoic acid plays a role in cholesterol and bile acid homeostasis, wheras ALDH1a which produces retinoic acid, is expressed at low levels in Sik3(-/-) mice. Lipid metabolism disorders in Sik3(-/-) mice are ameliorated by the treatment with 9-cis-retinoic acid. In conclusion, SIK3 is a novel energy regulator that modulates cholesterol and bile acid metabolism by coupling with retinoid metabolism, and may alter the size of energy storage in mice.
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Affiliation(s)
- Tatsuya Uebi
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Yumi Itoh
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Osamu Hatano
- Department of Anatomy, Nara Medical University, Nara, Japan
| | - Ayako Kumagai
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
- Department of Life Science and Biotechnology, Kansai University, Suita, Osaka, Japan
| | - Masato Sanosaka
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Tsutomu Sasaki
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Satoru Sasagawa
- Department of Bone and Cartilage Biology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Junko Doi
- Food and Nutrition, Senri Kinran University, Osaka, Japan
| | - Keita Tatsumi
- Department of Laboratory Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Kuniko Mitamura
- Faculty of Pharmaceutical Sciences, Kinki University, Osaka, Japan
| | - Eiichi Morii
- Department of Pathology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Katsuyuki Aozasa
- Department of Pathology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Tomohiro Kawamura
- Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Meinoshin Okumura
- Department of General Thoracic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Jun Nakae
- Frontier Medicine on Metabolic Syndrome, Keio University School of Medicine, Tokyo, Japan
| | - Hajime Takikawa
- Department of Medicine, Teikyo University School of Medicine, Tokyo, Japan
| | - Toshio Fukusato
- Department of Pathology, Teikyo University School of Medicine, Tokyo, Japan
| | - Minako Koura
- Animal Models for Human Diseases, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Mayumi Nish
- Department of Anatomy, Nara Medical University, Nara, Japan
| | - Anders Hamsten
- Cardiovascular Genetics and Genomics, Atherosclerosis Research Unit, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Angela Silveira
- Cardiovascular Genetics and Genomics, Atherosclerosis Research Unit, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Alejandro M. Bertorello
- Membrane Signaling Networks, Atherosclerosis Research Unit, Karolinska Institutet, CMM, Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Kazuo Kitagawa
- Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yasuo Nagaoka
- Department of Life Science and Biotechnology, Kansai University, Suita, Osaka, Japan
| | - Hidehisa Kawahara
- Department of Life Science and Biotechnology, Kansai University, Suita, Osaka, Japan
| | - Takeshi Tomonaga
- Laboratory of Proteome Research, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Tetsuji Naka
- Laboratory for Immune Signal, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Shigeo Ikegawa
- Faculty of Pharmaceutical Sciences, Kinki University, Osaka, Japan
| | - Noriyuki Tsumaki
- Department of Bone and Cartilage Biology, Osaka University Graduate School of Medicine, Osaka, Japan
- Department of Cell Growth and Differentiation, Center for iPS Cell Research and Application, Kyoto University, Kyoto, Japan
| | - Junichiro Matsuda
- Animal Models for Human Diseases, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
| | - Hiroshi Takemori
- Laboratory of Cell Signaling and Metabolic Disease, National Institute of Biomedical Innovation, Ibaraki, Osaka, Japan
- * E-mail:
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6
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Eneling K, Brion L, Pinto V, Pinho MJ, Sznajder JI, Mochizuki N, Emoto K, Soares-da-Silva P, Bertorello AM. Salt-inducible kinase 1 regulates E-cadherin expression and intercellular junction stability. FASEB J 2012; 26:3230-9. [PMID: 22522110 DOI: 10.1096/fj.12-205609] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The protein kinase liver kinase B1 (LKB1) regulates cell polarity and intercellular junction stability. Also, LKB1 controls the activity of salt-inducible kinase 1 (SIK1). The role and relevance of SIK1 and its downstream effectors in linking the LKB1 signals within these processes are partially understood. We hypothesize that SIK1 may link LKB1 signals to the maintenance of epithelial junction stability by regulating E-cadherin expression. Results from our studies using a mouse lung alveolar epithelial (MLE-12) cell line or human renal proximal tubule (HK2) cell line transiently or stably lacking the expression of SIK1 (using SIK1 siRNAs or shRNAs), or with its expression abrogated (sik1(+/+) vs. sik1(-/-) mice), indicate that suppression of SIK1 (∼40%) increases the expression of the transcriptional repressors Snail2 (∼12-fold), Zeb1 (∼100%), Zeb2 (∼50%), and TWIST (∼20-fold) by activating cAMP-response element binding protein. The lack of SIK1 and activation of transcriptional repressors decreases the availability of E-cadherin (mRNA and protein expression by ∼100 and 80%, respectively) and the stability of intercellular junctions in epithelia (decreases in transepithelial resistance). Furthermore, LKB1-mediated increases in E-cadherin expression are impaired in cells where SIK1 has been disabled. We conclude that SIK1 is a key regulator of E-cadherin expression, and thereby contributes to the stability of intercellular junctions.
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Affiliation(s)
- Kristina Eneling
- Membrane Signaling Networks, Atherosclerosis Research Unit, Department of Medicine, Karolinska Institutet, Center for Molecular Medicine, Karolinska University Hospital-Solna, Stockholm, Sweden
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Popov S, Venetsanou K, Chedrese PJ, Pinto V, Takemori H, Franco-Cereceda A, Eriksson P, Mochizuki N, Soares-da-Silva P, Bertorello AM. Increases in intracellular sodium activate transcription and gene expression via the salt-inducible kinase 1 network in an atrial myocyte cell line. Am J Physiol Heart Circ Physiol 2012; 303:H57-65. [PMID: 22467310 DOI: 10.1152/ajpheart.00512.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cardiac hypertrophy (CH) generally occurs as the result of the sustained mechanical stress caused by elevated systemic arterial blood pressure (BP). However, in animal models, elevated salt intake is associated with CH even in the absence of significant increases in BP. We hypothesize that CH is not exclusively the consequence of mechanical stress but also of other factors associated with elevated BP such as abnormal cell sodium homeostasis. We examined the effect of small increases in intracellular sodium concentration ([Na(+)](i)) on transcription factors and genes associated with CH in a cardiac cell line. Increases in [Na(+)](i) led to a time-dependent increase in the expression levels of mRNA for natriuretic peptide and myosin heavy chain genes and also increased myocyte enhancer factor (MEF)2/nuclear factor of activated T cell (NFAT) transcriptional activity. Increases in [Na(+)](i) are associated with activation of salt-inducible kinase 1 (snflk-1, SIK1), a kinase known to be critical for cardiac development. Moreover, increases in [Na(+)](i) resulted in increased SIK1 expression. Sodium did not increase MEF2/NFAT activity or gene expression in cells expressing a SIK1 that lacked kinase activity. The mechanism by which SIK1 activated MEF2 involved phosphorylation of HDAC5. Increases in [Na(+)](i) activate SIK1 and MEF2 via a parallel increase in intracellular calcium through the reverse mode of Na(+)/Ca(2+)-exchanger and activation of CaMK1. These data obtained in a cardiac cell line suggest that increases in intracellular sodium could influence myocardial growth by controlling transcriptional activation and gene expression throughout the activation of the SIK1 network.
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Affiliation(s)
- Sergej Popov
- Membrane Signaling Networks, Atherosclerosis Research Unit, Department of Medicine, CMM, Karolinska Institutet, Karolinska University Hospital-Solna, Stockholm, Sweden
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Eneling K, Chen J, Welch LC, Takemori H, Sznajder JI, Bertorello AM. Salt-inducible kinase 1 is present in lung alveolar epithelial cells and regulates active sodium transport. Biochem Biophys Res Commun 2011; 409:28-33. [PMID: 21549091 DOI: 10.1016/j.bbrc.2011.04.100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 04/22/2011] [Indexed: 10/18/2022]
Abstract
Salt-inducible kinase 1 (SIK1) in epithelial cells mediates the increases in active sodium transport (Na(+), K(+)-ATPase-mediated) in response to elevations in the intracellular concentration of sodium. In lung alveolar epithelial cells increases in active sodium transport in response to β-adrenergic stimulation increases pulmonary edema clearance. Therefore, we sought to determine whether SIK1 is present in lung epithelial cells and to examine whether isoproterenol-dependent stimulation of Na(+), K(+)-ATPase is mediated via SIK1 activity. All three SIK isoforms were present in airway epithelial cells, and in alveolar epithelial cells type 1 and type 2 from rat and mouse lungs, as well as from human and mouse cell lines representative of lung alveolar epithelium. In mouse lung epithelial cells, SIK1 associated with the Na(+), K(+)-ATPase α-subunit, and isoproterenol increased SIK1 activity. Isoproterenol increased Na(+), K(+)-ATPase activity and the incorporation of Na(+), K(+)-ATPase molecules at the plasma membrane. Furthermore, those effects were abolished in cells depleted of SIK1 using shRNA, or in cells overexpressing a SIK1 kinase-deficient mutant. These results provide evidence that SIK1 is present in lung epithelial cells and that its function is relevant for the action of isoproterenol during regulation of active sodium transport. As such, SIK1 may constitute an important target for drug discovery aimed at improving the clearance of pulmonary edema.
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Affiliation(s)
- Kristina Eneling
- Membrane Signaling Networks, Atherosclerosis Research Unit, Department of Medicine, CMM, Karolinska Institutet, Karolinska University Hospital-Solna, Stockholm, Sweden
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Jaitovich A, Bertorello AM. Intracellular sodium sensing: SIK1 network, hormone action and high blood pressure. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1140-9. [PMID: 20347966 DOI: 10.1016/j.bbadis.2010.03.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 03/12/2010] [Accepted: 03/20/2010] [Indexed: 01/11/2023]
Abstract
Sodium is the main determinant of body fluid distribution. Sodium accumulation causes water retention and, often, high blood pressure. At the cellular level, the concentration and active transport of sodium is handled by the enzyme Na(+),K(+)-ATPase, whose appearance enabled evolving primitive cells to cope with osmotic stress and contributed to the complexity of mammalian organisms. Na(+),K(+)-ATPase is a platform at the hub of many cellular signaling pathways related to sensing intracellular sodium and dealing with its detrimental excess. One of these pathways relies on an intracellular sodium-sensor network with the salt-inducible kinase 1 (SIK1) at its core. When intracellular sodium levels rise, and after the activation of calcium-related signals, this network activates the Na(+),K(+)-ATPase and expel the excess of sodium from the cytosol. The SIK1 network also mediates sodium-independent signals that modulate the activity of the Na(+),K(+)-ATPase, like dopamine and angiotensin, which are relevant per se in the development of high blood pressure. Animal models of high blood pressure, with identified mutations in components of multiple pathways, also have alterations in the SIK1 network. The introduction of some of these mutants into normal cells causes changes in SIK1 activity as well. Some cellular processes related to the metabolic syndrome, such as insulin effects on the kidney and other tissues, also appear to involve the SIK1. Therefore, it is likely that this protein, by modulating active sodium transport and numerous hormonal responses, represents a "crossroad" in the development and adaptation to high blood pressure and associated diseases.
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Affiliation(s)
- Ariel Jaitovich
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital-Solna, 171 76 Stockholm, Sweden.
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10
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Abstract
Chronic hypertension is characterized by a persistent increase in vascular tone. Sodium-rich diets promote hypertension; however, the underlying molecular mechanisms are not fully understood. Variations in the sodium content of the diet, through hormonal mediators such as dopamine and angiotensin II, modulate renal tubule Na(+),K(+)-ATPase activity. Stimulation of Na(+),K(+)-ATPase activity increases sodium transport across the renal proximal tubule epithelia, promoting Na(+) retention, whereas inhibited Na(+),K(+)-ATPase activity decreases sodium transport, and thereby natriuresis. Diets rich in sodium also enhance the release of adrenal endogenous ouabain-like compounds (OLC), which inhibit Na(+),K(+)-ATPase activity, resulting in increased intracellular Na(+) and Ca(2+) concentrations in vascular smooth muscle cells, thus increasing the vascular tone, with a corresponding increase in blood pressure. The mechanisms by which these homeostatic processes are integrated in response to salt intake are complex and not completely elucidated. However, recent scientific findings provide new insights that may offer additional avenues to further explore molecular mechanisms related to normal physiology and pathophysiology of various forms of hypertension (i.e. salt-induced). Consequently, new strategies for the development of improved therapeutics and medical management of hypertension are anticipated.
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Affiliation(s)
- Ariel Jaitovich
- Membrane Signaling Networks, Atherosclerosis Research Unit, Department of Medicine, Karolinska Institutet, Karolinska University Hospital-Solna, 171 76 Stockholm, Sweden.
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Chen Z, Leibiger I, Katz AI, Bertorello AM. Pals-associated tight junction protein functionally links dopamine and angiotensin II to the regulation of sodium transport in renal epithelial cells. Br J Pharmacol 2009; 158:486-93. [PMID: 19563532 DOI: 10.1111/j.1476-5381.2009.00299.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND AND PURPOSE Dopamine inhibits renal cell Na(+),K(+)-ATPase activity and cell sodium transport by promoting the internalization of active molecules from the plasma membrane, whereas angiotensin II (ATII) stimulates its activity by recruiting new molecules to the plasma membrane. They achieve such effects by activating multiple and distinct signalling molecules in a hierarchical manner. The purpose of this study was to investigate whether dopamine and ATII utilize scaffold organizer proteins as components of their signalling networks, in order to avoid deleterious cross talk. EXPERIMENTAL APPROACH Attention was focused on a multiple PDZ domain protein, Pals-associated tight junction protein (PATJ). Ectopic expression of PATJ in renal epithelial cells in culture was used to study its interaction with components of the dopamine signalling cascade. Similarly, expression of PATJ deletion mutants was employed to analyse its functional relevance during dopamine-, ATII- and insulin-dependent regulation of Na(+),K(+)-ATPase. KEY RESULTS Dopamine receptors and components of its signalling cascade mediating inhibition of Na(+),K(+)-ATPase interact with PATJ. Inhibition of Na(+),K(+)-ATPase by dopamine was prevented by expression of mutants of PATJ lacking PDZ domains 2, 4 or 5; whereas the stimulatory effect of ATII and insulin on Na(+),K(+)-ATPase was blocked by expression of PATJ lacking PDZ domains 1, 4 or 5. CONCLUSIONS AND IMPLICATIONS A multiple PDZ domain protein may add functionality to G protein-coupled and tyrosine kinase receptors signalling during regulation of Na(+),K(+)-ATPase. Signalling molecules and effectors can be integrated into a functional network by the scaffold organizer protein PATJ via its multiple PDZ domains.
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Affiliation(s)
- Z Chen
- Department of Medicine, Karolinska Institutet, Karolinska University Hospital-Solna, Stockholm, Sweden
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Efendiev R, Budu CE, Bertorello AM, Pedemonte CH. G-protein-coupled receptor-mediated traffic of Na,K-ATPase to the plasma membrane requires the binding of adaptor protein 1 to a Tyr-255-based sequence in the alpha-subunit. J Biol Chem 2008; 283:17561-7. [PMID: 18420589 PMCID: PMC2427321 DOI: 10.1074/jbc.m709260200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 04/15/2008] [Indexed: 11/06/2022] Open
Abstract
Motion of integral membrane proteins to the plasma membrane in response to G-protein-coupled receptor signals requires selective cargo recognition motifs that bind adaptor protein 1 and clathrin. Angiotensin II, through the activation of AT1 receptors, promotes the recruitment to the plasma membrane of Na,K-ATPase molecules from intracellular compartments. We present evidence to demonstrate that a tyrosine-based sequence (IVVY-255) present within the Na,K-ATPase alpha1-subunit is involved in the binding of adaptor protein 1. Mutation of Tyr-255 to a phenylalanine residue in the Na,K-ATPase alpha1-subunit greatly reduces the angiotensin II-dependent activation of Na,K-ATPase, recruitment of Na,K-ATPase molecules to the plasma membrane, and association of adaptor protein 1 with Na,K-ATPase alpha1-subunit molecules. To determine protein-protein interaction, we used fluorescence resonance energy transfer between fluorophores attached to the Na,K-ATPase alpha1-subunit and adaptor protein 1. Although angiotensin II activation of AT1 receptors induces a significant increase in the level of fluorescence resonance energy transfer between the two molecules, this effect was blunted in cells expressing the Tyr-255 mutant. Thus, results from different methods and techniques suggest that the Tyr-255-based sequence within the NKA alpha1-subunit is the site of adaptor protein 1 binding in response to the G-protein-coupled receptor signals produced by angiotensin II binding to AT1 receptors.
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Affiliation(s)
- Riad Efendiev
- College of Pharmacy, University of Houston, Houston, Texas 77204, USA.
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Efendiev R, Das-Panja K, Cinelli AR, Bertorello AM, Pedemonte CH. Localization of intracellular compartments that exchange Na,K-ATPase molecules with the plasma membrane in a hormone-dependent manner. Br J Pharmacol 2007; 151:1006-13. [PMID: 17533417 PMCID: PMC2042937 DOI: 10.1038/sj.bjp.0707304] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE Dopamine is a major regulator of sodium reabsorption in proximal tubule epithelia. By binding to D1-receptors, dopamine induces endocytosis of plasma membrane Na,K-ATPase, resulting in a reduced capacity of the cells to transport sodium, thus contributing to natriuresis. We have previously demonstrated several aspects of the molecular mechanism by which dopamine induces Na,K-ATPase endocytosis; however, the location of intracellular compartments containing Na,K-ATPase molecules has not been identified. EXPERIMENTAL APPROACH In this study, we used different approaches to determine the localization of Na,K-ATPase-containing intracellular compartments. By expression of fluorescent-tagged Na,K-ATPase molecules in opossum kidney cells, a cell culture model of proximal tubule epithelia, we used fluorescence microscopy to determine cellular distribution of the fluorescent molecules and the effects of dopamine on this distribution. By labelling cell surface Na,K-ATPase molecules from the cell exterior with either biotin or an epitope-tagged antibody, we determined the localization of the tagged Na,K-ATPase molecules after endocytosis induced by dopamine. KEY RESULTS In cells expressing fluorescent-tagged Na,K-ATPase molecules, there were intracellular compartments containing Na,K-ATPase molecules. These compartments were in very close proximity to the plasma membrane. Upon treatment of the cells with dopamine, the fluorescence labelling of these compartments was increased. The labelling of these compartments was also observed when the endocytosis of biotin- or antibody-tagged plasma membrane Na,K-ATPase molecules was induced by dopamine. CONCLUSIONS AND IMPLICATIONS The intracellular compartments containing Na,K-ATPase molecules are located just underneath the plasma membrane.
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Affiliation(s)
- R Efendiev
- College of Pharmacy, University of Houston, 4800 Calhoun Road, Houston, TX 77204, USA.
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Abstract
Na(+), K(+)-adenosine triphosphatase is a ubiquitous enzyme present in higher eukaryotes responsible for the maintenance of ionic gradients across the plasma membrane. It creates appropriate conditions for critical cellular processes such as secondary transport of solutes and water, for pH regulation, and also for creating an electrical potential that gives singular qualities to excitable cells. It also served as a platform for a higher level of cellular complexity because many important signaling networks appear to be downstream events of the pump's function. Renal physiology and pathology are affected significantly by its presence, and it seems that both molecular and pharmacologic manipulations of its action can create different venues to deal with diverse disease states.
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Affiliation(s)
- A Ariel Jaitovich
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA.
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Efendiev R, Cinelli AR, Leibiger IB, Bertorello AM, Pedemonte CH. FRET analysis reveals a critical conformational change within the Na,K-ATPase α1 subunit N-terminus during GPCR-dependent endocytosis. FEBS Lett 2006; 580:5067-70. [PMID: 16949583 DOI: 10.1016/j.febslet.2006.08.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 08/08/2006] [Accepted: 08/14/2006] [Indexed: 11/24/2022]
Abstract
Dopamine is a major regulator of sodium reabsorption in proximal tubule epithelia. It induces the endocytosis of plasma membrane Na,K-ATPase molecules, and this results in a reduced capacity of the cells to transport sodium. Dopamine induces the phosphorylation of Ser-18 in the alpha1-subunit of Na,K-ATPase. Fluorescence resonance energy transfer analysis of cells expressing YFP-alpha1 and beta1-CFP reveals that treatment of the cells with dopamine increases energy transfer between CFP and YFP. This is consistent with a protein conformational change that results in the N-terminal end of alpha1 moving closer to the internal face of the plasma membrane.
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Affiliation(s)
- Riad Efendiev
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, 4800 Calhoun Road, Houston, TX 77204-5037, USA.
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Chen Z, Krmar RT, Dada L, Efendiev R, Leibiger IB, Pedemonte CH, Katz AI, Sznajder JI, Bertorello AM. Phosphorylation of adaptor protein-2 mu2 is essential for Na+,K+-ATPase endocytosis in response to either G protein-coupled receptor or reactive oxygen species. Am J Respir Cell Mol Biol 2006; 35:127-32. [PMID: 16498080 PMCID: PMC2658693 DOI: 10.1165/rcmb.2006-0044oc] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Activation of G protein-coupled receptor by dopamine and hypoxia-generated reactive oxygen species promote Na+,K+-ATPase endocytosis. This effect is clathrin dependent and involves the activation of protein kinase C (PKC)-zeta and phosphorylation of the Na+,K+-ATPase alpha-subunit. Because the incorporation of cargo into clathrin vesicles requires association with adaptor proteins, we studied whether phosphorylation of adaptor protein (AP)-2 plays a role in its binding to the Na+,K+-ATPase alpha-subunit and thereby in its endocytosis. Dopamine induces a time-dependent phosphorylation of the AP-2 mu2 subunit. Using specific inhibitors and dominant-negative mutants, we establish that this effect was mediated by activation of the adaptor associated kinase 1/PKC-zeta isoform. Expression of the AP-2 mu2 bearing a mutation in its phosphorylation site (T156A) prevented Na+,K+-ATPase endocytosis and changes in activity induced by dopamine. Similarly, in lung alveolar epithelial cells, hypoxia-induced endocytosis of Na+,K+-ATPase requires the binding of AP-2 to the tyrosine-based motif (Tyr-537) located in the Na+,K+-ATPase alpha-subunit, and this effect requires phosphorylation of the AP-2 mu2 subunit. We conclude that phosphorylation of AP-2 mu2 subunit is essential for Na+,K+-ATPase endocytosis in response to a variety of signals, such as dopamine or reactive oxygen species.
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Affiliation(s)
- Zongpei Chen
- Department of Medicine, Membrane Signaling Networks, Karolinska Institutet, Karolinska Hospital, Stockholm, Sweden
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Bertorello AM, Sznajder JI. The dopamine paradox in lung and kidney epithelia: sharing the same target but operating different signaling networks. Am J Respir Cell Mol Biol 2005; 33:432-7. [PMID: 16234332 PMCID: PMC2715350 DOI: 10.1165/rcmb.2005-0297tr] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Stimulation of dopamine receptors in the lung or kidney epithelia has distinct and opposite effects on the function of Na,K-ATPase, which results in increased Na(+) absorption across the alveolar epithelium and increased sodium excretion via the kidney epithelium. In the lung, dopamine increases Na,K-ATPase by increasing cell basolateral surface expression of Na(+),K(+)-ATPase molecules, whereas in the kidney epithelia it decreases Na(+),K(+)-ATPase activity by removing active units from the plasma membrane by endocytosis. The opposite effects of dopamine over the same target (the Na(+),K(+)-ATPase) involve the activation of a distinct signaling network that it is target specific, and has a different spatial resolution. Understanding the specific signaling pathways involved in these actions of dopamine and their hierarchical organization may facilitate the drug discovery process that could lead to the design of new therapeutic approaches to clear lung edema in patients with acute lung injury and to decrease fluid overload during congestive heart failure and hypertension.
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Affiliation(s)
- Alejandro M Bertorello
- Department of Medicine, Atherosclerosis Research Unit, Membrane Signaling Networks, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
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Abstract
In the current report we review the results that lay grounds for the model of intracellular sodium-mediated dopamine-induced endocytosis of Na,K-ATPase. Under conditions of a high salt diet, dopamine activates PKCzeta, which phosphorylates NKA alpha1 Ser-18. The phosphorylation produces a conformational change of alpha1 NH2-terminus, which through interaction with other domains of alpha1 exposes PI3K- and AP-2-binding domains. PI3K bound to the NKA alpha1 induces the recruitment and activation of other proteins involved in endocytosis, and PI3K-generated 3-phosphoinositides affect the local cytoskeleton and modify the biophysical conditions of the membrane for development of clathrin-coated pits. Plasma membrane phosphorylated NKA is internalized to specialized intracellular compartments where the NKA will be dephosphorylated. The NKA internalization results in a reduced Na+ transport by proximal tubule epithelial cells.
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Efendiev R, Chen Z, Krmar RT, Uhles S, Katz AI, Pedemonte CH, Bertorello AM. The 14-3-3 protein translates the NA+,K+-ATPase {alpha}1-subunit phosphorylation signal into binding and activation of phosphoinositide 3-kinase during endocytosis. J Biol Chem 2005; 280:16272-7. [PMID: 15722354 DOI: 10.1074/jbc.m500486200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clathrin-dependent endocytosis of Na(+),K(+)-ATPase molecules in response to G protein-coupled receptor signals is triggered by phosphorylation of the alpha-subunit and the binding of phosphoinositide 3-kinase. In this study, we describe a molecular mechanism linking phosphorylation of Na(+),K(+)-ATPase alpha-subunit to binding and activation of phosphoinositide 3-kinase. Co-immunoprecipitation studies, as well as experiments using confocal microscopy, revealed that dopamine favored the association of 14-3-3 protein with the basolateral plasma membrane and its co-localization with the Na(+),K(+)-ATPase alpha-subunit. The functional relevance of this interaction was established in opossum kidney cells expressing a 14-3-3 dominant negative mutant, where dopamine failed to decrease Na(+),K(+)-ATPase activity and to promote its endocytosis. The phosphorylated Ser-18 residue within the alpha-subunit N terminus is critical for 14-3-3 binding. Activation of phosphoinositide 3-kinase by dopamine during Na(+),K(+)-ATPase endocytosis requires the binding of the kinase to a proline-rich domain within the alpha-subunit, and this effect was blocked by the presence of a 14-3-3 dominant negative mutant. Thus, the 14-3-3 protein represents a critical linking mechanism for recruiting phosphoinositide 3-kinase to the site of Na(+),K(+)-ATPase endocytosis.
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Affiliation(s)
- Riad Efendiev
- Department of Medicine, Atherosclerosis Research Unit, Membrane Signaling Networks, Karolinska Institutet, Karolinska University Hospital-Solna, S-171 76 Stockholm, Sweden
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Efendiev R, Krmar RT, Ogimoto G, Zwiller J, Tripodi G, Katz AI, Bianchi G, Pedemonte CH, Bertorello AM. Hypertension-linked mutation in the adducin alpha-subunit leads to higher AP2-mu2 phosphorylation and impaired Na+,K+-ATPase trafficking in response to GPCR signals and intracellular sodium. Circ Res 2004; 95:1100-8. [PMID: 15528469 DOI: 10.1161/01.res.0000149570.20845.89] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Alpha-adducin polymorphism in humans is associated with abnormal renal sodium handling and high blood pressure. The mechanisms by which mutations in adducin affect the renal set point for sodium excretion are not known. Decreases in Na+,K+-ATPase activity attributable to endocytosis of active units in renal tubule cells by dopamine regulates sodium excretion during high-salt diet. Milan rats carrying the hypertensive adducin phenotype have a higher renal tubule Na+,K+-ATPase activity, and their Na+,K+-ATPase molecules do not undergo endocytosis in response to dopamine as do those of the normotensive strain. Dopamine fails to promote the interaction between adaptins and the Na+,K+-ATPase because of adaptin-mu2 subunit hyperphosphorylation. Expression of the hypertensive rat or human variant of adducin into normal renal epithelial cells recreates the hypertensive phenotype with higher Na+,K+-ATPase activity, mu2-subunit hyperphosphorylation, and impaired Na+,K+-ATPase endocytosis. Thus, increased renal Na+,K+-ATPase activity and altered sodium reabsorption in certain forms of hypertension could be attributed to a mutant form of adducin that impairs the dynamic regulation of renal Na+,K+-ATPase endocytosis in response to natriuretic signals.
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Affiliation(s)
- Riad Efendiev
- Department of Medicine, Atherosclerosis Research Unit, Membrane Signaling Networks, Karolinska Institutet, Karolinska University Hospital, S-171 76 Stockholm, Sweden
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21
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Khundmiri SJ, Bertorello AM, Delamere NA, Lederer ED. Clathrin-mediated Endocytosis of Na+,K+-ATPase in Response to Parathyroid Hormone Requires ERK-dependent Phosphorylation of Ser-11 within the α1-Subunit. J Biol Chem 2004; 279:17418-27. [PMID: 14976217 DOI: 10.1074/jbc.m311715200] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Parathyroid hormone (PTH) inhibits Na(+),K(+)-ATPase activity through protein kinase C- (PKC) and extracellular signal-regulated kinase- (ERK) dependent pathways and increases serine phosphorylation of the alpha(1)-subunit. To determine whether specific serine phosphorylation sites within the Na(+),K(+)-ATPase alpha(1)-subunit are involved in the Na(+),K(+)-ATPase responses to PTH, we examined the effect of PTH in opossum kidney cells stably transfected with wild type rat Na(+),K(+)-ATPase alpha(1)-subunit (WT), serine 11 to alanine mutant alpha(1)-subunit (S11A), or serine 18 to alanine mutant alpha(1)-subunit (S18A). PTH increased phosphorylation and endocytosis of the Na(+),K(+)-ATPase alpha(1)-subunit into clathrin-coated vesicles in cells transfected with WT and S18A rat Na(+),K(+)-ATPase alpha(1)-subunits. PTH did not increase the level of phosphorylation or stimulate translocation of Na(+),K(+)-ATPase alpha(1)-subunits into clathrin-coated vesicles in cells transfected with the S11A mutant. PTH inhibited ouabain-sensitive (86)Rb uptake and Na(+),K(+)-ATPase activity (ouabain-sensitive ATP hydrolysis) in WT- and S18A-transfected opossum kidney cells but not in S11A-transfected cells. Pretreatment of the cells with the PKC inhibitors and ERK inhibitor blocked PTH inhibition of (86)Rb uptake, Na(+),K(+)-ATPase activity, alpha(1)-subunit phosphorylation, and endocytosis in WT and S18A cells. Consistent with the notion that ERK phosphorylates Na(+),K(+)-ATPase alpha(1)-subunit, ERK was shown to be capable of causing phosphorylation of Na(+),K(+)-ATPase alpha(1)-subunit immunoprecipitated from WT and S18A but not from S11A-transfected cells. These results suggest that PTH regulates Na(+),K(+)-ATPase by PKC and ERK-dependent alpha(1)-subunit phosphorylation and that the phosphorylation requires the expression of a serine at the 11 position of the Na(+),K(+)-ATPase alpha(1)-subunit.
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Adir Y, Azzam ZS, Lecuona E, Leal S, Pesce L, Dumasius V, Bertorello AM, Factor P, Young JB, Ridge KM, Sznajder JI. Augmentation of Endogenous Dopamine Production Increases Lung Liquid Clearance. Am J Respir Crit Care Med 2004; 169:757-63. [PMID: 14701706 DOI: 10.1164/rccm.200207-744oc] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We have previously reported that dopamine increased active Na+ transport in rat lungs by upregulating the alveolar epithelial Na,K-ATPase. Here we tested whether alveolar epithelial cells produce dopamine and whether increasing endogenous dopamine production by feeding rats a 4% tyrosine diet (TSD) would increase lung liquid clearance. Alveolar Type II cells express the enzyme aromatic-L-amino acid decarboxylase (AADC) and, when incubated with the dopamine precursor, 3-hydroxy-L-tyrosine (L-dopa), produce dopamine. Rats fed TSD, a precursor of L-dopa and dopamine, had increased urinary dopamine levels, which were inhibited by benserazide, an inhibitor of AADC. Rats fed TSD for 15, 24, and 48 hours had a 26, 46, and 45% increase in lung liquid clearance, respectively, as compared with controls. Also, dopaminergic D1 receptor antagonist--but not dopaminergic D2 receptor antagonist--inhibited the TSD-mediated increase in lung liquid clearance. Alveolar Type II cells isolated from the lungs of rats after they had been fed TSD for 24 hours demonstrated increased protein abundance of Na,K-ATPase alpha1 and beta1 subunits. Basolateral membranes isolated from peripheral lung tissue of tyrosine-fed rats had increased Na,K-ATPase activity and Na,K-ATPase alpha1 subunit. These data provide the first evidence that alveolar epithelial cells produce dopamine and that increasing endogenous dopamine increases lung liquid clearance.
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Affiliation(s)
- Yochai Adir
- Department of Medicine, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611-3010, USA
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23
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Mendez CF, Leibiger IB, Leibiger B, Høy M, Gromada J, Berggren PO, Bertorello AM. Rapid association of protein kinase C-epsilon with insulin granules is essential for insulin exocytosis. J Biol Chem 2003; 278:44753-7. [PMID: 12941947 DOI: 10.1074/jbc.m308664200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glucose-dependent exocytosis of insulin requires activation of protein kinase C (PKC). However, because of the great variety of isoforms and their ubiquitous distribution within the beta-cell, it is difficult to predict the importance of a particular isoform and its mode of action. Previous data revealed that two PKC isoforms (alpha and epsilon) translocate to membranes in response to glucose (Zaitzev, S. V., Efendic, S., Arkhammar, P., Bertorello, A. M., and Berggren, P. O. (1995) Proc. Natl. Acad. Sci. U. S. A. 92, 9712-9716). Using confocal microscopy, we have now established that in response to glucose, PKC-epsilon but not PKC-alpha associates with insulin granules and that green fluorescent protein-tagged PKC-epsilon changes its distribution within the cell periphery upon stimulation of beta-cells with glucose. Definite evidence of PKC-epsilon requirement during insulin granule exocytosis was obtained by using a dominant negative mutant of this isoform. The presence of this mutant abolished glucose-induced insulin secretion, whereas transient expression of the wild-type PKC-epsilon led to a significant increase in insulin exocytosis. These results suggest that association of PKC-epsilon with insulin granule membranes represents an important component of the secretory network because it is essential for insulin exocytosis in response to glucose.
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Affiliation(s)
- Carlos F Mendez
- Rolf Luft Center for Diabetes Research, Department of Molecular Medicine, Karolinska Institutet, Karolinska Hospital, SE-171 76 Stockholm, Sweden
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24
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Efendiev R, Budu CE, Cinelli AR, Bertorello AM, Pedemonte CH. Intracellular Na+ regulates dopamine and angiotensin II receptors availability at the plasma membrane and their cellular responses in renal epithelia. J Biol Chem 2003; 278:28719-26. [PMID: 12759348 DOI: 10.1074/jbc.m303741200] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The balance and cross-talk between natruretic and antinatruretic hormone receptors plays a critical role in the regulation of renal Na+ homeostasis, which is a major determinant of blood pressure. Dopamine and angiotensin II have antagonistic effects on renal Na+ and water excretion, which involves regulation of the Na+,K+-ATPase activity. Herein we demonstrate that angiotensin II (Ang II) stimulation of AT1 receptors in proximal tubule cells induces the recruitment of Na+,K+-ATPase molecules to the plasmalemma, in a process mediated by protein kinase Cbeta and interaction of the Na+,K+-ATPase with adaptor protein 1. Ang II stimulation led to phosphorylation of the alpha subunit Ser-11 and Ser-18 residues, and substitution of these amino acids with alanine residues completely abolished the Ang II-induced stimulation of Na+,K+-ATPase-mediated Rb+ transport. Thus, for Ang II-dependent stimulation of Na+,K+-ATPase activity, phosphorylation of these serine residues is essential and may constitute a triggering signal for recruitment of Na+,K+-ATPase molecules to the plasma membrane. When cells were treated simultaneously with saturating concentrations of dopamine and Ang II, either activation or inhibition of the Na+,K+-ATPase activity was produced dependent on the intracellular Na+ concentration, which was varied in a very narrow physiological range (9-19 mm). A small increase in intracellular Na+ concentrations induces the recruitment of D1 receptors to the plasma membrane and a reduction in plasma membrane AT1 receptors. Thus, one or more proteins may act as an intracellular Na+ concentration sensor and play a major regulatory role on the effect of hormones that regulate proximal tubule Na+ reabsorption.
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Affiliation(s)
- Riad Efendiev
- College of Pharmacy, University of Houston, Houston, Texas 77204, USA
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25
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Olsen HL, Hoy M, Zhang W, Bertorello AM, Bokvist K, Capito K, Efanov AM, Meister B, Thams P, Yang SN, Rorsman P, Berggren PO, Gromada J. Phosphatidylinositol 4-kinase serves as a metabolic sensor and regulates priming of secretory granules in pancreatic beta cells. Proc Natl Acad Sci U S A 2003; 100:5187-92. [PMID: 12700357 PMCID: PMC154320 DOI: 10.1073/pnas.0931282100] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2002] [Accepted: 03/05/2003] [Indexed: 11/18/2022] Open
Abstract
Insulin secretion is controlled by the beta cell's metabolic state, and the ability of the secretory granules to undergo exocytosis increases during glucose stimulation in a membrane potential-independent fashion. Here, we demonstrate that exocytosis of insulin-containing secretory granules depends on phosphatidylinositol 4-kinase (PI 4-kinase) activity and that inhibition of this enzyme suppresses glucose-stimulated insulin secretion. Intracellular application of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)] stimulated exocytosis by promoting the priming of secretory granules for release and increasing the number of granules residing in a readily releasable pool. Reducing the cytoplasmic ADP concentration in a way mimicking the effects of glucose stimulation activated PI 4-kinase and increased exocytosis whereas changes of the ATP concentration in the physiological range had little effect. The PI(4,5)P(2)-binding protein Ca(2+)-dependent activator protein for secretion (CAPS) is present in beta cells, and neutralization of the protein abolished both Ca(2+)- and PI(4,5)P(2)-induced exocytosis. We conclude that ADP-induced changes in PI 4-kinase activity, via generation of PI(4,5)P(2), represents a metabolic sensor in the beta cell by virtue of its capacity to regulate the release competence of the secretory granules.
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Affiliation(s)
- Hervør L Olsen
- Islet Cell Physiology, Novo Nordisk AS, Novo Alle, DK-2880 Bagsvaerd, Denmark
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26
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Abstract
The Na(+),K(+)-ATPase traffics between the plasma membrane and intracellular compartments in response to acute changes in membrane receptor activation. These effects are accomplished by a time-dependent interaction of the Na(+),K(+)-ATPase alpha-subunit with specific intracellular signaling molecules either at the plasma membrane (endocytosis) or at the endosome's membranes (recruitment). Most of these studies have been performed in rat renal epithelial cells in which only the alpha(1) isoenzyme is present. Studies in neurons from the neostriatum in which all three alpha-subunit isoforms are present indicate that neurotransmitter-dependent regulation of Na(+),K(+)-ATPase activity displays isoform specificity and also suggest a more complex organization of the intracellular signaling networks controlling Na(+),K(+)-ATPase traffic in mammalian cells.
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Affiliation(s)
- Vera Lucas Teixeira
- Department of Medicine, Atherosclerosis Research Unit, Karolinska Institutet, Karolinska Hospital, 171 76 Stockholm, Sweden
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27
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Dada LA, Chandel NS, Ridge KM, Pedemonte C, Bertorello AM, Sznajder JI. Hypoxia-induced endocytosis of Na,K-ATPase in alveolar epithelial cells is mediated by mitochondrial reactive oxygen species and PKC-zeta. J Clin Invest 2003; 111:1057-64. [PMID: 12671055 PMCID: PMC152585 DOI: 10.1172/jci16826] [Citation(s) in RCA: 208] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
During ascent to high altitude and pulmonary edema, the alveolar epithelial cells (AEC) are exposed to hypoxic conditions. Hypoxia inhibits alveolar fluid reabsorption and decreases Na,K-ATPase activity in AEC. We report here that exposure of AEC to hypoxia induced a time-dependent decrease of Na,K-ATPase activity and a parallel decrease in the number of Na,K-ATPase alpha(1) subunits at the basolateral membrane (BLM), without changing its total cell protein abundance. These effects were reversible upon reoxygenation and specific, because the plasma membrane protein GLUT1 did not decrease in response to hypoxia. Hypoxia caused an increase in mitochondrial reactive oxygen species (ROS) levels that was inhibited by antioxidants. Antioxidants prevented the hypoxia-mediated decrease in Na,K-ATPase activity and protein abundance at the BLM. Hypoxia-treated AEC deficient in mitochondrial DNA (rho(0) cells) did not have increased levels of ROS, nor was the Na,K-ATPase activity inhibited. Na,K-ATPase alpha(1) subunit was phosphorylated by PKC in hypoxia-treated AEC. In AEC treated with a PKC-zeta antagonist peptide or with the Na,K-ATPase alpha(1) subunit lacking the PKC phosphorylation site (Ser-18), hypoxia failed to decrease Na,K-ATPase abundance and function. Accordingly, we provide evidence that hypoxia decreases Na,K-ATPase activity in AEC by triggering its endocytosis through mitochondrial ROS and PKC-zeta-mediated phosphorylation of the Na,K-ATPase alpha(1) subunit.
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Affiliation(s)
- Laura A Dada
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, Illinois 60611, USA
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28
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Bertorello AM, Komarova Y, Smith K, Leibiger IB, Efendiev R, Pedemonte CH, Borisy G, Sznajder JI. Analysis of Na+,K+-ATPase motion and incorporation into the plasma membrane in response to G protein-coupled receptor signals in living cells. Mol Biol Cell 2003; 14:1149-57. [PMID: 12631730 PMCID: PMC151586 DOI: 10.1091/mbc.e02-06-0367] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Dopamine (DA) increases Na(+),K(+)-ATPase activity in lung alveolar epithelial cells. This effect is associated with an increase in Na(+),K(+)-ATPase molecules within the plasma membrane (). Analysis of Na(+),K(+)-ATPase motion was performed in real-time in alveolar cells stably expressing Na(+),K(+)-ATPase molecules carrying a fluorescent tag (green fluorescent protein) in the alpha-subunit. The data demonstrate a distinct (random walk) pattern of basal movement of Na(+),K(+)-ATPase-containing vesicles in nontreated cells. DA increased the directional movement (by 3.5 fold) of the vesicles and an increase in their velocity (by 25%) that consequently promoted the incorporation of vesicles into the plasma membrane. The movement of Na(+),K(+)-ATPase-containing vesicles and incorporation into the plasma membrane were microtubule dependent, and disruption of this network perturbed vesicle motion toward the plasma membrane and prevented the increase in the Na(+),K(+)-ATPase activity induced by DA. Thus, recruitment of new Na(+),K(+)-ATPase molecules into the plasma membrane appears to be a major mechanism by which dopamine increases total cell Na(+),K(+)-ATPase activity.
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Affiliation(s)
- Alejandro M Bertorello
- Department of Medicine, Atherosclerosis Research Unit, Karolinska Institutet, Karolinska Hospital, S-171 76 Stockholm, Sweden.
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29
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Budu CE, Efendiev R, Cinelli AM, Bertorello AM, Pedemonte CH. Hormonal-dependent recruitment of Na+,K+-ATPase to the plasmalemma is mediated by PKC beta and modulated by [Na+]i. Br J Pharmacol 2002; 137:1380-6. [PMID: 12466249 PMCID: PMC1573600 DOI: 10.1038/sj.bjp.0704962] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The present study demonstrates that stimulation of hormonal receptors of proximal tubule cells with the serotonin-agonist 8-hydroxy-2-(di-n-propylamino) tetraline (8-OH-DPAT) induces an augmentation of Na(+),K(+)-ATPase activity that results from the recruitment of enzyme molecules to the plasmalemma. 2. Cells expressing the rodent wild-type Na(+),K(+)-ATPase alpha-subunit had the same basal Na(+),K(+)-ATPase activity as cells expressing the alpha-subunit S11A or S18A mutants, but stimulation of Na(+),K(+)-ATPase activity was completely abolished in either mutant. 3. 8-OH-DPAT treatment of OK cells led to PKC(beta)-dependent phosphorylation of the alpha-subunit Ser-11 and Ser-18 residues, and determination of enzyme activity with the S11A and S18A mutants indicated that both residues are essential for the agonist-dependent stimulation of Na(+),K(+)-ATPase activity. 4. When cells were treated with both dopamine and 8-OH-DPAT, an activation of Na(+),K(+)-ATPase was observed at basal intracellular sodium concentration (approximately 9 mM), and this activation was gradually reduced and became a significant inhibition as the concentration of intracellular sodium gradually increased from 9 to 19 mM. Thus, besides the antagonistic effects of dopamine and 8-OH-DPAT, intracellular sodium modulates whether an activation or an inhibition of Na(+),K(+)-ATPase is produced.
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Affiliation(s)
- Claudia E Budu
- College of Pharmacy, University of Houston, Houston, Texas, TX 77204, U.S.A
| | - Riad Efendiev
- College of Pharmacy, University of Houston, Houston, Texas, TX 77204, U.S.A
| | - Angel M Cinelli
- Department of Anatomy and Cell Biology, State University of New York, Brooklyn, New York, NY 11203, U.S.A
| | | | - Carlos H Pedemonte
- College of Pharmacy, University of Houston, Houston, Texas, TX 77204, U.S.A
- Author for correspondence:
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30
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Efendiev R, Yudowski GA, Zwiller J, Leibiger B, Katz AI, Berggren PO, Pedemonte CH, Leibiger IB, Bertorello AM. Relevance of dopamine signals anchoring dynamin-2 to the plasma membrane during Na+,K+-ATPase endocytosis. J Biol Chem 2002; 277:44108-14. [PMID: 12205083 DOI: 10.1074/jbc.m205173200] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Clathrin-dependent endocytosis of Na(+),K(+)-ATPase in response to dopamine regulates its catalytic activity in intact cells. Because fission of clathrin-coated pits requires dynamin, we examined the mechanisms by which dopamine receptor signals promote dynamin-2 recruitment and assembly at the site of Na(+),K(+)-ATPase endocytosis. Western blotting revealed that dopamine increased the association of dynamin-2 with the plasma membrane and with phosphatidylinositol 3-kinase. Dopamine inhibited Na(+),K(+)-ATPase activity in OK cells and in those overexpressing wild type dynamin-2 but not in cells expressing a dominant-negative mutant. Dephosphorylation of dynamin is important for its assembly. Dopamine increased protein phosphatase 2A activity and dephosphorylated dynamin-2. In cells expressing a dominant-negative mutant of protein phosphatase 2A, dopamine failed to dephosphorylate dynamin-2 and to reduce Na(+),K(+)-ATPase activity. Dynamin-2 is phosphorylated at Ser(848), and expression of the S848A mutant significantly blocked the inhibitory effect of dopamine. These results demonstrate a distinct signaling network originating from the dopamine receptor that regulates the state of dynamin-2 phosphorylation and that promotes its location (by interaction with phosphatidylinositol 3-kinase) at the site of Na(+),K(+)-ATPase endocytosis.
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Affiliation(s)
- Riad Efendiev
- Department of Molecular Medicine, The Rolf Luft Center for Diabetes Research, Karolinska Institutet, Karolinska Hospital, S-171 76 Stockholm, Sweden
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31
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Jaitovich AA, Bertorello AM. [Respiratory distress. New Perspectives to lung edema treatment]. Medicina (B Aires) 2002; 62:181-8. [PMID: 12038043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a life threatening condition associated with great morbidity and mortality. it is characterized initially by accumulation of fluid in the alveolar space that impairs alveolar oxygen exchange. Eventually, this syndrome leads to multiorgan failure. Therefore, rapid edema clearance has generally been associated with better outcome in patients with acute respiratory distress syndrome. Clearance of alveolar fluid is driven predominantly by active Na+ transport out of the alveolar space, mediated by increased apical Na(+)-channel and Na-K-ATPase activity. It has been demonstrated that increases in Na-K-ATPase in response to catecholamines in the alveolar epithelium are associated with increased lung edema clearance. The cellular mechanisms involve the recruitment of new Na-K-ATPase molecules to the plasma membrane from intracellular organelles. It also appears that adenovirus-mediated Na-K-ATPase gene transfer and increased Na-K-ATPase expression may provide an alternative and efficient pathway for transient increase in alveolar fluid reabsorption and resolution of pulmonary edema.
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Affiliation(s)
- A Ariel Jaitovich
- Departament of Molecular Medicine, Karolinska Hospital, Stockholm, Sweden.
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Høy M, Efanov AM, Bertorello AM, Zaitsev SV, Olsen HL, Bokvist K, Leibiger B, Leibiger IB, Zwiller J, Berggren PO, Gromada J. Inositol hexakisphosphate promotes dynamin I- mediated endocytosis. Proc Natl Acad Sci U S A 2002; 99:6773-7. [PMID: 12011438 PMCID: PMC124478 DOI: 10.1073/pnas.102157499] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Membrane homeostasis is maintained by exocytosis and endocytosis. The molecular mechanisms regulating the interplay between these two processes are not clear. Inositol hexakisphosphate (InsP(6)) is under metabolic control and serves as a signal in the pancreatic beta cell stimulus-secretion coupling by increasing Ca(2+)-channel activity and insulin exocytosis. We now show that InsP(6) also promotes dynamin I-mediated endocytosis in the pancreatic beta cell. This effect of InsP(6) depends on calcineurin-induced dephosphorylation and is accounted for by both activation of protein kinase C and inhibition of the phosphoinositide phosphatase synaptojanin and thereby formation of phosphatidylinositol 4,5-bisphosphate. In regulating both exocytosis and endocytosis, InsP(6) thus may have an essential integral role in membrane trafficking.
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Affiliation(s)
- Marianne Høy
- Laboratory of Islet Cell Physiology, Novo Nordisk A/S, Novo Alle, DK-2880 Bagsvaerd, Denmark
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33
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Doné SC, Leibiger IB, Efendiev R, Katz AI, Leibiger B, Berggren PO, Pedemonte CH, Bertorello AM. Tyrosine 537 within the Na+,K+-ATPase alpha-subunit is essential for AP-2 binding and clathrin-dependent endocytosis. J Biol Chem 2002; 277:17108-11. [PMID: 11859087 DOI: 10.1074/jbc.m201326200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In renal epithelial cells endocytosis of Na(+),K(+)-ATPase molecules is initiated by phosphorylation of its alpha(1)-subunit, leading to activation of phosphoinositide 3-kinase and adaptor protein-2 (AP-2)/clathrin recruitment. The present study was performed to establish the identity of the AP-2 recognition domain(s) within the Na(+),K(+)-ATPase alpha(1)-subunit. We identified a conserved sequence (Y(537)LEL) within the alpha(1)-subunit that represents an AP-2 binding site. Binding of AP-2 to the Na(+),K(+)-ATPase alpha(1)-subunit in response to dopamine (DA) was increased in OK cells stably expressing the wild type rodent alpha-subunit (OK-WT), but not in cells expressing the Y537A mutant (OK-Y537A). DA treatment was associated with increased alpha(1)-subunit abundance in clathrin vesicles from OK-WT but not from OK-Y537A cells. In addition, this mutation also impaired the ability of DA to inhibit Na(+),K(+)-ATPase activity. Because phorbol esters increase Na(+),K(+)-ATPase activity in OK cells, and this effect was not affected by the Y537A mutation, the present results suggest that the identified motif is specifically required for DA-induced AP-2 binding and Na(+),K(+)-ATPase endocytosis.
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Affiliation(s)
- Stefania Cotta Doné
- Department of Molecular Medicine, Karolinska Institutet, The Rolf Luft Centrum for Diabetes Research, Karolinska Hospital, 171 76 Stockholm, Sweden
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Ridge KM, Dada L, Lecuona E, Bertorello AM, Katz AI, Mochly-Rosen D, Sznajder JI. Dopamine-induced exocytosis of Na,K-ATPase is dependent on activation of protein kinase C-epsilon and -delta. Mol Biol Cell 2002; 13:1381-9. [PMID: 11950946 PMCID: PMC102276 DOI: 10.1091/mbc.01-07-0323] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The purpose of this study was to define mechanisms by which dopamine (DA) regulates the Na,K-ATPase in alveolar epithelial type 2 (AT2) cells. The Na,K-ATPase activity increased by twofold in cells incubated with either 1 microM DA or a dopaminergic D(1) agonist, fenoldopam, but not with the dopaminergic D(2) agonist quinpirole. The increase in activity paralleled an increase in Na,K-ATPase alpha1 and beta1 protein abundance in the basolateral membrane (BLM) of AT2 cells. This increase in protein abundance was mediated by the exocytosis of Na,K-pumps from late endosomal compartments into the BLM. Down-regulation of diacylglycerol-sensitive types of protein kinase C (PKC) by pretreatment with phorbol 12-myristate 13-acetate or inhibition with bisindolylmaleimide prevented the DA-mediated increase in Na,K-ATPase activity and exocytosis of Na,K-pumps to the BLM. Preincubation of AT2 cells with either 2-[1-(3-dimethylaminopropyl)-5-methoxyindol-3-yl]-3-(1H-indol-3-yl)maleimide (Gö6983), a selective inhibitor of PKC-delta, or isozyme-specific inhibitor peptides for PKC-delta or PKC-epsilon inhibited the DA-mediated increase in Na,K-ATPase. PKC-delta and PKC-epsilon, but not PKC-alpha or -beta, translocated from the cytosol to the membrane fraction after exposure to DA. PKC-delta- and PKC-epsilon-specific peptide agonists increased Na,K-ATPase protein abundance in the BLM. Accordingly, dopamine increased Na,K-ATPase activity in alveolar epithelial cells through the exocytosis of Na,K-pumps from late endosomes into the basolateral membrane in a mechanism-dependent activation of the novel protein kinase C isozymes PKC-delta and PKC-epsilon.
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Affiliation(s)
- Karen M Ridge
- Pulmonary and Critical Care Medicine, Northwestern University Medical School, Chicago, IL 60611, USA
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35
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Efendiev R, Bertorello AM, Zandomeni R, Cinelli AR, Pedemonte CH. Agonist-dependent regulation of renal Na+,K+-ATPase activity is modulated by intracellular sodium concentration. J Biol Chem 2002; 277:11489-96. [PMID: 11796710 DOI: 10.1074/jbc.m108182200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We tested the hypothesis that the level of intracellular sodium modulates the hormonal regulation of the Na(+),K(+)-ATPase activity in proximal tubule cells. By using digital imaging fluorescence microscopy of a sodium-sensitive dye, we determined that the sodium ionophore monensin induced a dose-specific increase of intracellular sodium. A correspondence between the elevation of intracellular sodium and the level of dopamine-induced inhibition of Na(+),K(+)-ATPase activity was determined. At basal intracellular sodium concentration, stimulation of cellular protein kinase C by phorbol 12-myristate 13-acetate (PMA) promoted a significant increase in Na(+),K(+)-ATPase activity; however, this activation was gradually reduced as the concentration of intracellular sodium was increased to become a significant inhibition at concentrations of intracellular sodium higher than 16 mm. Under these conditions, PMA and dopamine share the same signaling pathway to inhibit the Na(+),K(+)-ATPase. The effects of PMA and dopamine on the Na(+),K(+)-ATPase activity and the modulation of these effects by different intracellular sodium concentrations were not modified when extracellular and intracellular calcium were almost eliminated. These results suggest that the level of intracellular sodium modulates whether hormones stimulate, inhibit, or have no effect on the Na(+),K(+)-ATPase activity leading to a tight control of sodium reabsorption.
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Affiliation(s)
- Riad Efendiev
- College of Pharmacy, University of Houston, Houston, Texas 77204, USA
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36
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Pedemont CH, Bertorello AM. Short-term regulation of the proximal tubule Na+,K+-ATPase: increased/decreased Na+,K+-ATPase activity mediated by protein kinase C isoforms. J Bioenerg Biomembr 2001; 33:439-47. [PMID: 11762919 DOI: 10.1023/a:1010675708820] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In different species and tissues, a great variety of hormones modulate Na+,K+-ATPase activity in a short-term fashion. Such regulation involves the activation of distinct intracellular signaling networks that are often hormone- and tissue-specific. This minireview focuses on our own experimental observations obtained by studying the regulation of the rodent proximal tubule Na+,K+-ATPase. We discuss evidence that hormones responsible for regulating kidney proximal tubule sodium reabsorption may not affect the intrinsic catalytic activity of the Na+,K+-ATPase, but rather the number of active units within the plasma membrane due to shuttling Na+,K+-ATPase molecules between intracellular compartments and the plasma membrane. These processes are mediated by different isoforms of protein kinase C and depend largely on variations in intracellular sodium concentrations.
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Affiliation(s)
- C H Pedemont
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Texas 77204-5515, USA.
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Johansen JE, Teixeira VL, Johansson C, Serrão P, Berggren PO, Soares-Da-Silva P, Schalling M, Bertorello AM. Altered dopaminergic transmission in the anorexic anx/anx mouse striatum. Neuroreport 2001; 12:2737-41. [PMID: 11522958 DOI: 10.1097/00001756-200108280-00029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We demonstrate abnormal dopaminergic neurotransmission in anorexic mice, homozygous for a recessive mutation (anx) causing starvation and motor disturbances. Isolated neurons from anx/anx striatum displayed a markedly increased activity of the Na+,K+-ATPase compared with normal littermates. Dopamine down-regulates Na+,K+-ATPase activity in striatal medium spiny neurons in rat, mouse and guinea pig. However, addition of dopamine in vitro failed to suppress the increased activity in anx/anx striatal neurons. Striatal dopamine and its metabolites, but not norepinephrine, were slightly but significantly lower in anx/anx mice than in normal littermates. We suggest that abnormal dopaminergic transmission may contribute to the anx phenotype.
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Affiliation(s)
- J E Johansen
- Department of Molecular Medicine, Karolinska Institutet, Karolinska Hospital, 171 76 Stockholm, Sweden.
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Efendiev R, Bertorello AM, Pressley TA, Rousselot M, Féraille E, Pedemonte CH. Simultaneous phosphorylation of Ser11 and Ser18 in the alpha-subunit promotes the recruitment of Na(+),K(+)-ATPase molecules to the plasma membrane. Biochemistry 2000; 39:9884-92. [PMID: 10933807 DOI: 10.1021/bi0007831] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Renal sodium homeostasis is a major determinant of blood pressure and is regulated by several natriuretic and antinatriuretic hormones. These hormones, acting through intracellular second messengers, either activate or inhibit proximal tubule Na(+),K(+)-ATPase. We have shown previously that phorbol ester (PMA) stimulation of endogenous PKC leads to activation of Na(+),K(+)-ATPase in cultured proximal tubule cells (OK cells) expressing the rodent Na(+), K(+)-ATPase alpha-subunit. We have now demonstrated that the treatment with PMA leads to an increased amount of Na(+),K(+)-ATPase molecules in the plasmalemma, which is proportional to the increased enzyme activity. Colchicine, dinitrophenol, and potassium cyanide prevented the PMA-dependent stimulation of activity without affecting the increased level of phosphorylation of the Na(+), K(+)-ATPase alpha-subunit. This suggests that phosphorylation does not directly stimulate Na(+),K(+)-ATPase activity; instead, phosphorylation may be the triggering mechanism for recruitment of Na(+),K(+)-ATPase molecules to the plasma membrane. Transfected cells expressing either an S11A or S18A mutant had the same basal Na(+),K(+)-ATPase activity as cells expressing the wild-type rodent alpha-subunit, but PMA stimulation of Na(+),K(+)-ATPase activity was completely abolished in either mutant. PMA treatment led to phosphorylation of the alpha-subunit by stimulation of PKC-beta, and the extent of this phosphorylation was greatly reduced in the S11A and S18A mutants. These results indicate that both Ser11 and Ser18 of the alpha-subunit are essential for PMA stimulation of Na(+), K(+)-ATPase activity, and that these amino acids are phosphorylated during this process. The results presented here support the hypothesis that PMA regulation of Na(+),K(+)-ATPase is the result of an increased number of Na(+),K(+)-ATPase molecules in the plasma membrane.
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Affiliation(s)
- R Efendiev
- College of Pharmacy, University of Houston, Houston, Texas 77204, Department of Molecular Medicine, Karolinska Institutet, S-171 76 Stockholm, Sweden
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Yudowski GA, Efendiev R, Pedemonte CH, Katz AI, Berggren PO, Bertorello AM. Phosphoinositide-3 kinase binds to a proline-rich motif in the Na+, K+-ATPase alpha subunit and regulates its trafficking. Proc Natl Acad Sci U S A 2000; 97:6556-61. [PMID: 10823893 PMCID: PMC18657 DOI: 10.1073/pnas.100128297] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Endocytosis of Na(+),K(+)-ATPase molecules in response to G protein-coupled receptor stimulation requires activation of class I(A) phosphoinositide-3 kinase (PI3K-I(A)) in a protein kinase C-dependent manner. In this paper, we report that PI3K-I(A), through its p85alpha subunit-SH3 domain, binds to a proline-rich region in the Na(+),K(+)-ATPase catalytic alpha subunit. This interaction is enhanced by protein kinase C-dependent phosphorylation of a serine residue that flanks the proline-rich motif in the Na(+),K(+)-ATPase alpha subunit and results in increased PI3K-I(A) activity, an effect necessary for adaptor protein 2 binding and clathrin recruitment. Thus, Ser-phosphorylation of the Na(+),K(+)-ATPase catalytic subunit serves as an anchor signal for regulating the location of PI3K-I(A) and its activation during Na(+),K(+)-ATPase endocytosis in response to G protein-coupled receptor signals.
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Affiliation(s)
- G A Yudowski
- The Rolf Luft Center for Diabetes Research, Karolinska Hospital, Department of Molecular Medicine, Karolinska Institutet, S-17176 Stockholm, Sweden
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40
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Ogimoto G, Yudowski GA, Barker CJ, Köhler M, Katz AI, Féraille E, Pedemonte CH, Berggren PO, Bertorello AM. G protein-coupled receptors regulate Na+,K+-ATPase activity and endocytosis by modulating the recruitment of adaptor protein 2 and clathrin. Proc Natl Acad Sci U S A 2000; 97:3242-7. [PMID: 10716725 PMCID: PMC16223 DOI: 10.1073/pnas.97.7.3242] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Inhibition of Na(+),K(+)-ATPase (NKA) activity in renal epithelial cells by activation of G protein-coupled receptors is mediated by phosphorylation of the catalytic alpha-subunit followed by endocytosis of active molecules. We examined whether agonists that counteract this effect do so by dephosphorylation of the alpha-subunit or by preventing its internalization through a direct interaction with the endocytic network. Oxymetazoline counteracted the action of dopamine on NKA activity, and this effect was achieved not by preventing alpha-subunit phosphorylation, but by impaired endocytosis of alpha-subunits into clathrin vesicles and early and late endosomes. Dopamine-induced inhibition of NKA activity and alpha-subunit endocytosis required the interaction of adaptor protein 2 (AP-2) with the catalytic alpha-subunit. Phosphorylation of the alpha-subunit is essential because dopamine failed to promote such interaction in cells lacking the protein kinase C phosphorylation residue (S18A). Confocal microscopy confirmed that oxymetazoline prevents incorporation of NKA molecules into clathrin vesicles by inhibiting the ability of dopamine to recruit clathrin to the plasma membrane. Dopamine decreased the basal levels of inositol hexakisphosphate (InsP(6)), whereas oxymetazoline prevented this effect. Similar increments (above basal) in the concentration of InsP(6) induced by oxymetazoline prevented AP-2 binding to the NKA alpha-subunit in response to dopamine. In conclusion, inhibition of NKA activity can be reversed by preventing its endocytosis without altering the state of alpha-subunit phosphorylation; increased InsP(6) in response to G protein-coupled receptor signals blocks the recruitment of AP-2 and thereby clathrin-dependent endocytosis of NKA.
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Affiliation(s)
- G Ogimoto
- Department of Molecular Medicine, Karolinska Institutet, The Rolf Luft Center for Diabetes Research, Karolinska Hospital, 171 76 Stockholm, Sweden
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Barnard ML, Ridge KM, Saldias F, Friedman E, Gare M, Guerrero C, Lecuona E, Bertorello AM, Katz AI, Sznajder JI. Stimulation of the dopamine 1 receptor increases lung edema clearance. Am J Respir Crit Care Med 1999; 160:982-6. [PMID: 10471628 DOI: 10.1164/ajrccm.160.3.9812003] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
We previously reported that lung edema clearance was stimulated by dopamine (DA). The purpose of this study was to determine whether the DA-mediated stimulation of edema clearance occurs via an adrenergic or dopaminergic regulation of alveolar epithelial Na, K-ATPase. When isolated perfused rat lungs were coinstilled with DA and SCH 23390 (a specific D(1) receptor antagonist), there was a dose-dependent attenuation of the stimulatory effects of DA. Coinstillation with S-sulpiride (a specific D(2) receptor antagonist) or propranolol (a beta-adrenergic antagonist) did not alter DA-stimulated clearance. Similarly, the specific dopaminergic D(1) agonist fenoldopam increased lung edema clearance, but quinpirole (a specific dopaminergic D(2) agonist) did not. (125)I-SCH 23982 binding studies suggested that D(1) receptors are expressed on alveolar type II (ATII) cells with an apparent dissociation constant (K(d)) of 4.4 nM and binding maximum (Bmax) 9.8 pmol/mg. Consistent with these results, the D(1) receptor messenger RNA (mRNA) and protein were detected in ATII cells by reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. These data demonstrate a novel mechanism involving the activation of dopaminergic D(1) receptors which mediates DA-stimulated edema removal from rat lungs.
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Affiliation(s)
- M L Barnard
- Michael Reese Hospital and Medical Center, Pulmonary and Critical Care Medicine and Northwestern University Medical School, Chicago, Illinois, USA
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Yang SN, Larsson O, Bränström R, Bertorello AM, Leibiger B, Leibiger IB, Moede T, Köhler M, Meister B, Berggren PO. Syntaxin 1 interacts with the L(D) subtype of voltage-gated Ca(2+) channels in pancreatic beta cells. Proc Natl Acad Sci U S A 1999; 96:10164-9. [PMID: 10468580 PMCID: PMC17860 DOI: 10.1073/pnas.96.18.10164] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Interaction of syntaxin 1 with the alpha(1D) subunit of the voltage-gated L type Ca(2+) channel was investigated in the pancreatic beta cell. Coexpression of the enhanced green fluorescent protein-linked alpha(1D) subunit with the enhanced blue fluorescent protein-linked syntaxin 1 and Western blot analysis together with subcellular fractionation demonstrated that the alpha(1D) subunit and syntaxin 1 were colocalized in the plasma membrane. Furthermore, the alpha(1D) subunit was coimmunoprecipitated efficiently by a polyclonal antibody against syntaxin 1. Syntaxin 1 also played a central role in the modulation of L type Ca(2+) channel activity because there was a faster Ca(2+) current run-down in cells incubated with antisyntaxin 1 compared with controls. In parallel, antisyntaxin 1 markedly reduced insulin release in both intact and permeabilized cells, subsequent to depolarization with K(+) or exposure to high Ca(2+). Exchanging Ca(2+) for Ba(2+) abolished the effect of antisyntaxin 1 on both Ca(2+) channel activity and insulin exocytosis. Moreover, antisyntaxin 1 had no significant effects on Ca(2+)-independent insulin release trigged by hypertonic stimulation. This suggests that there is a structure-function relationship between the alpha(1D) subunit of the L type Ca(2+) channel and the exocytotic machinery in the pancreatic beta cell.
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Affiliation(s)
- S N Yang
- The Rolf Luft Center for Diabetes Research, Department of Molecular Medicine, Karolinska Institutet, Karolinska Hospital, S-171 76 Stockholm, Sweden
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Abstract
Dopamine (DA) inhibits rodent proximal tubule Na+,K+-ATPase via stimulation of protein kinase C (PKC). However, direct stimulation of PKC by phorbol 12-myristate 13-acetate (PMA) results in increased Na+,K+-ATPase. LY333531, a specific inhibitor of the PKC-beta isoform, prevents PMA-dependent activation of Na+,K+-ATPase, but has no effect on DA inhibition of this activity. A similar result was obtained with a PKC-beta inhibitor peptide. Concentrations of staurosporine, that inhibits PKC-zeta, prevent DA-dependent inhibition of Na+,K+-ATPase and a similar effect was obtained with a PKC-zeta inhibitor peptide. Thus, PMA-dependent stimulation of Na+,K+-ATPase is mediated by activation of PKC-beta, whereas inhibition by DA requires activation of PKC-zeta.
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Affiliation(s)
- R Efendiev
- College of Pharmacy, University of Houston, TX 77204-5515, USA
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Chibalin AV, Ogimoto G, Pedemonte CH, Pressley TA, Katz AI, Féraille E, Berggren PO, Bertorello AM. Dopamine-induced endocytosis of Na+,K+-ATPase is initiated by phosphorylation of Ser-18 in the rat alpha subunit and Is responsible for the decreased activity in epithelial cells. J Biol Chem 1999; 274:1920-7. [PMID: 9890946 DOI: 10.1074/jbc.274.4.1920] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Dopamine inhibits Na+,K+-ATPase activity in renal tubule cells. This inhibition is associated with phosphorylation and internalization of the alpha subunit, both events being protein kinase C-dependent. Studies of purified preparations, fusion proteins with site-directed mutagenesis, and heterologous expression systems have identified two major protein kinase C phosphorylation residues (Ser-11 and Ser-18) in the rat alpha1 subunit isoform. To identify the phosphorylation site(s) that mediates endocytosis of the subunit in response to dopamine, we have performed site-directed mutagenesis of these residues in the rat alpha1 subunit and expressed the mutated forms in a renal epithelial cell line. Dopamine inhibited Na+,K+-ATPase activity and increased alpha subunit phosphorylation and clathrin-dependent endocytosis into endosomes in cells expressing the wild type alpha1 subunit or the S11A alpha1 mutant, and both effects were blocked by protein kinase C inhibition. In contrast, dopamine did not elicit any of these effects in cells expressing the S18A alpha1 mutant. While Ser-18 phosphorylation is necessary for endocytosis, it does not affect per se the enzymatic activity: preventing endocytosis with wortmannin or LY294009 blocked the inhibitory effect of dopamine on Na+,K+-ATPase activity, although it did not alter the increased alpha subunit phosphorylation induced by this agonist. We conclude that dopamine-induced inhibition of Na+, K+-ATPase activity in rat renal tubule cells requires endocytosis of the alpha subunit into defined intracellular compartments and that phosphorylation of Ser-18 is essential for this process.
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Affiliation(s)
- A V Chibalin
- Department of Molecular Medicine, Karolinska Institutet, The Rolf Luft Center for Diabetes Research, Karolinska Hospital, S-171 76 Stockholm, Sweden
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45
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Owada S, Larsson O, Arkhammar P, Katz AI, Chibalin AV, Berggren PO, Bertorello AM. Glucose decreases Na+,K+-ATPase activity in pancreatic beta-cells. An effect mediated via Ca2+-independent phospholipase A2 and protein kinase C-dependent phosphorylation of the alpha-subunit. J Biol Chem 1999; 274:2000-8. [PMID: 9890957 DOI: 10.1074/jbc.274.4.2000] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the pancreatic beta-cell, glucose-induced membrane depolarization promotes opening of voltage-gated L-type Ca2+ channels, an increase in cytoplasmic free Ca2+ concentration ([Ca2+]i), and exocytosis of insulin. Inhibition of Na+,K+-ATPase activity by ouabain leads to beta-cell membrane depolarization and Ca2+ influx. Because glucose-induced beta-cell membrane depolarization cannot be attributed solely to closure of ATP-regulated K+ channels, we investigated whether glucose regulates other transport proteins, such as the Na+,K+-ATPase. Glucose inhibited Na+,K+-ATPase activity in single pancreatic islets and intact beta-cells. This effect was reversible and required glucose metabolism. The inhibitory action of glucose was blocked by pretreatment of the islets with a selective inhibitor of a Ca2+-independent phospholipase A2. Arachidonic acid, the hydrolytic product of this phospholipase A2, also inhibited Na+, K+-ATPase activity. This effect, like that of glucose, was blocked by nordihydroguaiaretic acid, a selective inhibitor of the lipooxygenase metabolic pathway, but not by inhibitors of the cyclooxygenase or cytochrome P450-monooxygenase pathways. The lipooxygenase product 12(S)-HETE (12-S-hydroxyeicosatetranoic acid) inhibited Na+,K+-ATPase activity, and this effect, as well as that of glucose, was blocked by bisindolylmaleimide, a specific protein kinase C inhibitor. Moreover, glucose increased the state of alpha-subunit phosphorylation by a protein kinase C-dependent process. These results demonstrate that glucose inhibits Na+, K+-ATPase activity in beta-cells by activating a distinct intracellular signaling network. Inhibition of Na+,K+-ATPase activity may thus be part of the mechanisms whereby glucose promotes membrane depolarization, an increase in [Ca2+]i, and thereby insulin secretion in the pancreatic beta-cell.
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Affiliation(s)
- S Owada
- Rolf Luft Center for Diabetes Research L6B:01, Department of Molecular Medicine, Karolinska Institutet, Karolinska Hospital, S-171 76 Stockholm, Sweden
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Bertorello AM, Ridge KM, Chibalin AV, Katz AI, Sznajder JI. Isoproterenol increases Na+-K+-ATPase activity by membrane insertion of alpha-subunits in lung alveolar cells. Am J Physiol 1999; 276:L20-7. [PMID: 9887051 DOI: 10.1152/ajplung.1999.276.1.l20] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Catecholamines promote lung edema clearance via beta-adrenergic-mediated stimulation of active Na+ transport across the alveolar epithelium. Because alveolar epithelial type II cell Na+-K+-ATPase contributes to vectorial Na+ flux, the present study was designed to investigate whether Na+-K+-ATPase undergoes acute changes in its catalytic activity in response to beta-adrenergic-receptor stimulation. Na+-K+-ATPase activity increased threefold in cells incubated with 1 microM isoproterenol for 15 min, which also resulted in a fourfold increase in the cellular levels of cAMP. Forskolin (10 microM) also stimulated Na+-K+-ATPase activity as well as ouabain binding. The increase in Na+-K+-ATPase activity was abolished when cells were coincubated with a cAMP-dependent protein kinase inhibitor. This stimulation, however, was not due to protein kinase-dependent phosphorylation of the Na+-K+-ATPase alpha-subunit; rather, it was the result of an increased number of alpha-subunits recruited from the late endosomes into the plasma membrane. The recruitment of alpha-subunits to the plasma membrane was prevented by stabilizing the cortical actin cytoskeleton with phallacidin or by blocking anterograde transport with brefeldin A but was unaffected by coincubation with amiloride. In conclusion, isoproterenol increases Na+-K+-ATPase activity in alveolar type II epithelial cells by recruiting alpha-subunits into the plasma membrane from an intracellular compartment in an Na+-independent manner.
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Affiliation(s)
- A M Bertorello
- Department of Molecular Medicine, Karolinska Institutet, Karolinska Hospital, S-171 76 Stockholm, Sweden
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47
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Vieira-Coelho MA, Teixeira VA, Finkel Y, Soares-Da-Silva P, Bertorello AM. Dopamine-dependent inhibition of jejunal Na+-K+-ATPase during high-salt diet in young but not in adult rats. Am J Physiol 1998; 275:G1317-23. [PMID: 9843768 DOI: 10.1152/ajpgi.1998.275.6.g1317] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
During high-salt diet endogenous dopamine (DA) reduces jejunal sodium transport in young but not in adult rats. This study was designed to evaluate whether this effect is mediated, at the cellular level, by inhibition of Na+-K+-ATPase activity. Enzyme activity was determined in isolated jejunal cells by the rate of [gamma-32P]ATP hydrolysis. Cells were obtained from weanling and adult rats fed either with high- or normal-salt diet. In 20-day-old but not in 40-day-old rats Na+-K+-ATPase activity was significantly reduced during high-salt diet. This inhibition was abolished by a blocker of DA synthesis. The decreased activity was associated with a decreased alpha1-subunit at the plasma membrane. During high-salt diet there was an increase in DA content in jejunal cells from 20-day-old rats, associated with a parallel decrease in 5-hydroxytryptamine, compared with normal-salt diet. In 40-day-old rats, however, the catecholamine level remained unchanged during high-salt diet. Incubation of isolated jejunal cells with DA resulted in a dose-dependent inhibition of Na+-K+-ATPase activity in 20- but not in 40-day-old rats. We conclude that during high-salt diet, jejunal Na+-K+-ATPase in 20-day-old rats is inhibited, and this effect is likely to be mediated by locally formed DA.
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Affiliation(s)
- M A Vieira-Coelho
- Departments of Molecular Medicine and Woman and Child Health, Karolinska Institute, Karolinska Hospital, 171 76 Stockholm, Sweden
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48
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Carranza ML, Rousselot M, Chibalin AV, Bertorello AM, Favre H, Féraille E. Protein kinase A induces recruitment of active Na+,K+-ATPase units to the plasma membrane of rat proximal convoluted tubule cells. J Physiol 1998; 511 ( Pt 1):235-43. [PMID: 9679177 PMCID: PMC2231118 DOI: 10.1111/j.1469-7793.1998.235bi.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/1998] [Accepted: 05/15/1998] [Indexed: 11/29/2022] Open
Abstract
1. The aim of this study was to investigate the mechanism of control of Na+,K+-ATPase activity by the cAMP-protein kinase A (PKA) pathway in rat proximal convoluted tubules. For this purpose, we studied the in vitro action of exogenous cAMP (10-3 M dibutyryl-cAMP (db-cAMP) or 8-bromo-cAMP) and endogenous cAMP (direct activation of adenylyl cyclases by 10-5 M forskolin) on Na+,K+-ATPase activity and membrane trafficking. 2. PKA activation stimulated both the cation transport and hydrolytic activity of Na+,K+-ATPase by about 40%. Transport activity stimulation was specific to the PKA signalling pathway since (1) db-cAMP stimulated the ouabain-sensitive 86Rb+ uptake in a time- and dose-dependent fashion; (2) this effect was abolished by addition of H-89 or Rp-cAMPS, two structurally different PKA inhibitors; and (3) this stimulation was not affected by inhibition of protein kinase C (PKC) by GF109203X. The stimulatory effect of db-cAMP on the hydrolytic activity of Na+,K+-ATPase was accounted for by an increased maximal ATPase rate (Vmax) without alteration of the efficiency of the pump, suggesting that cAMP-PKA pathway was implicated in membrane redistribution control. 3. To test this hypothesis, we used two different approaches: (1) cell surface protein biotinylation and (2) subcellular fractionation. Both approaches confirmed that the cAMP-PKA pathway was implicated in membrane trafficking regulation. The stimulation of Na+,K+-ATPase activity by db-cAMP was associated with an increase (+40%) in Na+, K+-ATPase units expressed at the cell surface which was assessed by Western blotting after streptavidin precipitation of biotinylated cell surface proteins. Subcellular fractionation confirmed the increased expression in pump units at the cell surface which was accompanied by a decrease (-30%) in pump units located in the subcellular fraction corresponding to early endosomes. 4. In conclusion, PKA stimulates Na+,K+-ATPase activity, at least in part, by increasing the number of Na+-K+ pumps in the plasma membrane in proximal convoluted tubule cells.
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Affiliation(s)
- M L Carranza
- Laboratoire de Nephrologie, Fondation pour Recherches Medicales, Avenue de la Roseraie 64, CH-1211 Geneve 4, Switzerland.
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49
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Chibalin AV, Zierath JR, Katz AI, Berggren PO, Bertorello AM. Phosphatidylinositol 3-kinase-mediated endocytosis of renal Na+, K+-ATPase alpha subunit in response to dopamine. Mol Biol Cell 1998; 9:1209-20. [PMID: 9571250 PMCID: PMC25342 DOI: 10.1091/mbc.9.5.1209] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Dopamine (DA) inhibition of Na+,K+-ATPase in proximal tubule cells is associated with increased endocytosis of its alpha and beta subunits into early and late endosomes via a clathrin vesicle-dependent pathway. In this report we evaluated intracellular signals that could trigger this mechanism, specifically the role of phosphatidylinositol 3-kinase (PI 3-K), the activation of which initiates vesicular trafficking and targeting of proteins to specific cell compartments. DA stimulated PI 3-K activity in a time- and dose-dependent manner, and this effect was markedly blunted by wortmannin and LY 294002. Endocytosis of the Na+,K+-ATPase alpha subunit in response to DA was also inhibited in dose-dependent manner by wortmannin and LY 294002. Activation of PI 3-K generally occurs by association with tyrosine kinase receptors. However, in this study immunoprecipitation with a phosphotyrosine antibody did not reveal PI 3-K activity. DA-stimulated endocytosis of Na+, K+-ATPase alpha subunits required protein kinase C, and the ability of DA to stimulate PI 3-K was blocked by specific protein kinase C inhibitors. Activation of PI 3-K is mediated via the D1 receptor subtype and the sequential activation of phospholipase A2, arachidonic acid, and protein kinase C. The results indicate a key role for activation of PI 3-K in the endocytic sequence that leads to internalization of Na+,K+-ATPase alpha subunits in response to DA, and suggest a mechanism for the participation of protein kinase C in this process.
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Affiliation(s)
- A V Chibalin
- Department of Molecular Medicine, Karolinska Institute, Karolinska Hospital, 171 76 Stockholm, Sweden
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50
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Chibalin AV, Pedemonte CH, Katz AI, Féraille E, Berggren PO, Bertorello AM. Phosphorylation of the catalyic alpha-subunit constitutes a triggering signal for Na+,K+-ATPase endocytosis. J Biol Chem 1998; 273:8814-9. [PMID: 9535860 DOI: 10.1074/jbc.273.15.8814] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Inhibition of Na+,K+-ATPase activity by dopamine is an important mechanism by which renal tubules modulate urine sodium excretion during a high salt diet. However, the molecular mechanisms of this regulation are not clearly understood. Inhibition of Na+,K+-ATPase activity in response to dopamine is associated with endocytosis of its alpha- and beta-subunits, an effect that is protein kinase C-dependent. In this study we used isolated proximal tubule cells and a cell line derived from opossum kidney and demonstrate that dopamine-induced endocytosis of Na+,K+-ATPase and inhibition of its activity were accompanied by phosphorylation of the alpha-subunit. Inhibition of both the enzyme activity and its phosphorylation were blocked by the protein kinase C inhibitor bisindolylmaleimide. The early time dependence of these processes suggests a causal link between phosphorylation and inhibition of enzyme activity. However, after 10 min of dopamine incubation, the alpha-subunit was no longer phosphorylated, whereas enzyme activity remained inhibited due to its removal from the plasma membrane. Dephosphorylation occurred in the late endosomal compartment. To further examine whether phosphorylation was a prerequisite for subunit endocytosis, we used the opossum kidney cell line transfected with the rodent alpha-subunit cDNA. Treatment of this cell line with dopamine resulted in phosphorylation and endocytosis of the alpha-subunit with a concomitant decrease in Na+,K+-ATPase activity. In contrast, none of these effects were observed in cells transfected with the rodent alpha-subunit that lacks the putative protein kinase C-phosphorylation sites (Ser11 and Ser18). Our results support the hypothesis that protein kinase C-dependent phosphorylation of the alpha-subunit is essential for Na+,K+-ATPase endocytosis and that both events are responsible for the decreased enzyme activity in response to dopamine.
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Affiliation(s)
- A V Chibalin
- Department of Molecular Medicine, Karolinska Institute, Karolinska Hospital, S-171 76 Stockholm, Sweden
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