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Paudel B, Gervasi MG, Porambo J, Caraballo DA, Tourzani DA, Mager J, Platt MD, Salicioni AM, Visconti PE. Sperm capacitation is associated with phosphorylation of the testis-specific radial spoke protein Rsph6a†. Biol Reprod 2020; 100:440-454. [PMID: 30239614 DOI: 10.1093/biolre/ioy202] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/03/2018] [Accepted: 09/13/2018] [Indexed: 12/31/2022] Open
Abstract
Mammalian sperm undergo a series of biochemical and physiological changes collectively known as capacitation in order to acquire the ability to fertilize. Although the increase in phosphorylation associated with mouse sperm capacitation is well established, the identity of the proteins involved in this signaling cascade remains largely unknown. Tandem mass spectrometry (MS/MS) has been used to identify the exact sites of phosphorylation and to compare the relative extent of phosphorylation at these sites. In the present work, we find that a novel site of phosphorylation on a peptide derived from the radial spoke protein Rsph6a is more phosphorylated in capacitated mouse sperm. The Rsph6a gene has six exons, five of which are conserved during evolution in flagellated cells. The exon containing the capacitation-induced phosphorylation site was found exclusively in eutherian mammals. Transcript analyses revealed at least two different testis-specific splicing variants for Rsph6a.Rsph6a mRNA expression was restricted to spermatocytes. Using antibodies generated against the Rsph6a N-terminal domain, western blotting and immunofluorescence analyses indicated that the protein remains in mature sperm and localizes to the sperm flagellum. Consistent with its role in the axoneme, solubility analyses revealed that Rsph6 is attached to cytoskeletal structures. Based on previous studies in Chlamydomonas reinhardtii, we predict that Rsph6 participates in the interaction between the central pair of microtubules and the surrounding pairs. The findings that Rsph6a is more phosphorylated during capacitation and is predicted to function in axonemal localization make Rsph6a a candidate protein mediating signaling processes in the sperm flagellum.
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Affiliation(s)
- Bidur Paudel
- Department of Veterinary and Animal Sciences, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - María Gracia Gervasi
- Department of Veterinary and Animal Sciences, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - James Porambo
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Diego A Caraballo
- IFIBYNE-CONICET, Laboratorio de Fisiología y Biología Molecular, Departamento de Fisiología, Biología Molecular y Celular, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Darya A Tourzani
- Department of Veterinary and Animal Sciences, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jesse Mager
- Department of Veterinary and Animal Sciences, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - Mark D Platt
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York, USA
| | - Ana María Salicioni
- Department of Veterinary and Animal Sciences, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
| | - Pablo E Visconti
- Department of Veterinary and Animal Sciences, Integrated Sciences Building, University of Massachusetts, Amherst, Massachusetts, USA
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Kanbay M, Yilmaz S, Dincer N, Ortiz A, Sag AA, Covic A, Sánchez-Lozada LG, Lanaspa MA, Cherney DZI, Johnson RJ, Afsar B. Antidiuretic Hormone and Serum Osmolarity Physiology and Related Outcomes: What Is Old, What Is New, and What Is Unknown? J Clin Endocrinol Metab 2019; 104:5406-5420. [PMID: 31365096 DOI: 10.1210/jc.2019-01049] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 07/25/2019] [Indexed: 12/16/2022]
Abstract
CONTEXT Although the physiology of sodium, water, and arginine vasopressin (AVP), also known as antidiuretic hormone, has long been known, accumulating data suggest that this system operates as a more complex network than previously thought. EVIDENCE ACQUISITION English-language basic science and clinical studies of AVP and osmolarity on the development of kidney and cardiovascular disease and overall outcomes. EVIDENCE SYNTHESIS Apart from osmoreceptors and hypovolemia, AVP secretion is modified by novel factors such as tongue acid-sensing taste receptor cells and brain median preoptic nucleus neurons. Moreover, pharyngeal, esophageal, and/or gastric sensors and gut microbiota modulate AVP secretion. Evidence is accumulating that increased osmolarity, AVP, copeptin, and dehydration are all associated with worse outcomes in chronic disease states such as chronic kidney disease (CKD), diabetes, and heart failure. On the basis of these pathophysiological relationships, an AVP receptor 2 blocker is now licensed for CKD related to polycystic kidney disease. CONCLUSION From a therapeutic perspective, fluid intake may be associated with increased AVP secretion if it is driven by loss of urine concentration capacity or with suppressed AVP if it is driven by voluntary fluid intake. In the current review, we summarize the literature on the relationship between elevated osmolarity, AVP, copeptin, and dehydration with renal and cardiovascular outcomes and underlying classical and novel pathophysiologic pathways. We also review recent unexpected and contrasting findings regarding AVP physiology in an attempt to explain and understand some of these relationships.
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Affiliation(s)
- Mehmet Kanbay
- Division of Nephrology, Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Sezen Yilmaz
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Neris Dincer
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Alberto Ortiz
- Dialysis Unit, School of Medicine, IIS-Fundacion Jimenez Diaz, Universidad Autónoma de Madrid, Madrid, Spain
| | - Alan A Sag
- Division of Vascular and Interventional Radiology, Department of Radiology, Duke University Medical Center, Durham, North Carolina
| | - Adrian Covic
- Nephrology Department, Dialysis and Renal Transplant Center, "Dr. C. I. Parhon" University Hospital, "Grigore T. Popa" University of Medicine and Pharmacy, Iasi, Romania
| | - Laura G Sánchez-Lozada
- Laboratory of Renal Physiopathology, Department of Nephrology, INC Ignacio Chávez, Mexico City, Mexico
| | - Miguel A Lanaspa
- Division of Renal Diseases and Hypertension, School of Medicine, University of Colorado Denver, Aurora, Colorado
| | - David Z I Cherney
- Department of Medicine, Division of Nephrology, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Richard J Johnson
- Division of Renal Diseases and Hypertension, School of Medicine, University of Colorado Denver, Aurora, Colorado
| | - Baris Afsar
- Division of Nephrology, Department of Medicine, Suleyman Demirel University School of Medicine, Isparta, Turkey
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Arif A, Jia J, Halawani D, Fox PL. Experimental approaches for investigation of aminoacyl tRNA synthetase phosphorylation. Methods 2016; 113:72-82. [PMID: 27729295 DOI: 10.1016/j.ymeth.2016.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 10/04/2016] [Accepted: 10/06/2016] [Indexed: 02/04/2023] Open
Abstract
Phosphorylation of many aminoacyl tRNA synthetases (AARSs) has been recognized for decades, but the contribution of post-translational modification to their primary role in tRNA charging and decryption of genetic code remains unclear. In contrast, phosphorylation is essential for performance of diverse noncanonical functions of AARSs unrelated to protein synthesis. Phosphorylation of glutamyl-prolyl tRNA synthetase (EPRS) has been investigated extensively in our laboratory for more than a decade, and has served as an archetype for studies of other AARSs. EPRS is a constituent of the IFN-γ-activated inhibitor of translation (GAIT) complex that directs transcript-selective translational control in myeloid cells. Stimulus-dependent phosphorylation of EPRS is essential for its release from the parental multi-aminoacyl tRNA synthetase complex (MSC), for binding to other GAIT complex proteins, and for regulating the binding to target mRNAs. Importantly, phosphorylation is the common driving force for the context- and stimulus-dependent release, and non-canonical activity, of other AARSs residing in the MSC, for example, lysyl tRNA synthetase (KARS). Here, we describe the concepts and experimental methodologies we have used to investigate the influence of phosphorylation on the structure and function of EPRS. We suggest that application of these approaches will help to identify new functional phosphorylation event(s) in other AARSs and elucidate their possible roles in noncanonical activities.
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Affiliation(s)
- Abul Arif
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jie Jia
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Dalia Halawani
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Paul L Fox
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
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4
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Sharabi K, Tavares CDJ, Rines AK, Puigserver P. Molecular pathophysiology of hepatic glucose production. Mol Aspects Med 2015; 46:21-33. [PMID: 26549348 DOI: 10.1016/j.mam.2015.09.003] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 09/09/2015] [Indexed: 12/23/2022]
Abstract
Maintaining blood glucose concentration within a relatively narrow range through periods of fasting or excess nutrient availability is essential to the survival of the organism. This is achieved through an intricate balance between glucose uptake and endogenous glucose production to maintain constant glucose concentrations. The liver plays a major role in maintaining normal whole body glucose levels by regulating the processes of de novo glucose production (gluconeogenesis) and glycogen breakdown (glycogenolysis), thus controlling the levels of hepatic glucose release. Aberrant regulation of hepatic glucose production (HGP) can result in deleterious clinical outcomes, and excessive HGP is a major contributor to the hyperglycemia observed in Type 2 diabetes mellitus (T2DM). Indeed, adjusting glycemia as close as possible to a non-diabetic range is the foremost objective in the medical treatment of patients with T2DM and is currently achieved in the clinic primarily through suppression of HGP. Here, we review the molecular mechanisms controlling HGP in response to nutritional and hormonal signals and discuss how these signals are altered in T2DM.
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Affiliation(s)
- Kfir Sharabi
- Department of Cancer Biology, Department of Cell Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Clint D J Tavares
- Department of Cancer Biology, Department of Cell Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Amy K Rines
- Department of Cancer Biology, Department of Cell Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Pere Puigserver
- Department of Cancer Biology, Department of Cell Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
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Hiroyama M, Fujiwara Y, Nakamura K, Aoyagi T, Mizutani R, Sanbe A, Tasaki R, Tanoue A. Altered lipid metabolism in vasopressin V1B receptor-deficient mice. Eur J Pharmacol 2009; 602:455-61. [DOI: 10.1016/j.ejphar.2008.11.043] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 11/12/2008] [Accepted: 11/24/2008] [Indexed: 10/21/2022]
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6
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Hiroyama M, Aoyagi T, Fujiwara Y, Birumachi J, Shigematsu Y, Kiwaki K, Tasaki R, Endo F, Tanoue A. Hypermetabolism of Fat in V1a Vasopressin Receptor Knockout Mice. Mol Endocrinol 2007; 21:247-58. [PMID: 17021052 DOI: 10.1210/me.2006-0069] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract[Arg8]Vasopressin (AVP) has an antilipolytic action on adipocytes, but little is known about the mechanisms involved. Here, we examined the involvement of the V1a receptor in the antilipolytic effect of AVP using V1a receptor-deficient (V1aR−/−) mice. The levels of blood glycerol were increased in V1aR−/− mice. The levels of ketone bodies, such as acetoacetic acid and 3-hydroxybutyric acid, the products of the lipid metabolism, were increased in V1aR−/− mice under a fasting condition. Triacylglyceride and free fatty acid levels in blood were decreased in V1aR−/− mice. Furthermore, measurements with tandem mass spectrometry determined that carnitine and acylcarnitines in serum, the products of β-oxidation, were increased in V1aR−/− mice. Most acylcarnitines were increased in V1aR−/− mice, especially in the case of 2-carbon (C2), C10:1, C10, C14:1, C16, C18:1, and hydroxy-18:1-carbon (OH-C18:1)-acylcarnitines under feeding rather than under fasting conditions. The analysis of tissue C2-acylcarnitine level showed that β-oxidation was promoted in muscle under the feeding condition and in liver under the fasting condition. An in vitro assay using brown adipocytes showed that the cells of V1aR−/− mice were more sensitive to isoproterenol for lipolysis. These results suggest that the lipid metabolism is enhanced in V1aR−/− mice. The cAMP level was enhanced in V1aR−/− mice in response to isoproterenol. The phosphorylation of Akt by insulin stimulation was reduced in V1aR−/− mice. These results suggest that insulin signaling is suppressed in V1aR−/− mice. In addition, the total bile acid, taurine, and cholesterol levels in blood were increased, and an enlargement of the cholecyst was observed in V1aR−/− mice. These results indicated that the production of bile acid was enhanced by the increased level of cholesterol and taurine. Therefore, these results indicated that AVP could modulate the lipid metabolism by the antilipolytic action and the synthesis of bile acid via the V1a receptor.
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Affiliation(s)
- Masami Hiroyama
- Department of Pharmacology, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo 157-8535, Japan
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Kaufman S. The phenylalanine hydroxylating system. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 67:77-264. [PMID: 8322620 DOI: 10.1002/9780470123133.ch2] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- S Kaufman
- Laboratory of Neurochemistry, National Institute of Mental Health, Bethesda, MD
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8
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Van Schaftingen E. Fructose 2,6-bisphosphate. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 59:315-95. [PMID: 3028056 DOI: 10.1002/9780470123058.ch7] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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9
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Exton JH. The roles of calcium and phosphoinositides in the mechanisms of alpha 1-adrenergic and other agonists. Rev Physiol Biochem Pharmacol 2005; 111:117-224. [PMID: 2906170 DOI: 10.1007/bfb0033873] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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10
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Vandana S, Navneet S, Surinder K, Krishnasastry MV. Modulation of EGF receptor autophosphorylation by alpha-hemolysin of Staphylococcus aureus via protein tyrosine phosphatase. FEBS Lett 2003; 535:71-6. [PMID: 12560081 DOI: 10.1016/s0014-5793(02)03862-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In the presence of assembled alpha-hemolysin (alpha-HL) of Staphylococcus aureus, the epidermal growth factor receptor (EGFr) is rapidly dephosphorylated. Several obvious possibilities that otherwise would have contributed to the dephosphorylation were ruled out. Instead, an elevation in the activity of a protein tyrosine phosphatase appears to be responsible for the observed loss of phosphorylation signal of EGFr. For this dephosphorylation, the assembly of alpha-HL is necessary while lytic pore formation is not required. In summary, the EGFr is unable to retain its phosphorylation signal in the presence of alpha-HL and the process is irreversible.
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Affiliation(s)
- Sharma Vandana
- National Center for Cell Science, Ganeshkind Road, Pune 411 007, India
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11
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Affiliation(s)
- J B Shabb
- Department of Biochemistry and Molecular Biology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, North Dakota 58202-9037, USA.
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12
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Paolisso G, Tagliamonte MR, De Lucia D, Palmieri F, Manzella D, Rinaldi C, Bossone A, Colaizzo D, Margaglione M, Varricchio M. ACE gene polymorphism and insulin action in older subjects and healthy centenarians. J Am Geriatr Soc 2001; 49:610-4. [PMID: 11380755 DOI: 10.1046/j.1532-5415.2001.49122.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES To evaluate the possible relationship between angiotensin-converting enzyme (ACE) insertion-deletion (ID) genotype and insulin resistance in a population of healthy older Italian subjects. DESIGN Prospective recruitment of a convenience sample. PARTICIPANTS One hundred twenty-five subjects age 62 to 105 in good health and not taking any drug known to interfere with glucose metabolism. RESULTS In the sample population, the relative frequencies of the ACE genotypes deletion-deletion (DD) (0.424), ID (0.400), and insertion-insertion (II) (0.176) were not significantly different from values predicted by Hardy-Weinberg equilibrium. The genotype distribution was similar in men and women. Subjects carrying the II genotype had a higher FPG (P <.001) and FPI (P <.001) than did subjects with DD or ID genotype. Subjects with II genotype also had a significantly higher HOMA index than did subjects with DD or ID genotype (P for trend <.002). In a multivariate stepwise regression analysis, the ACE ID polymorphism was significantly and independently associated with the HOMA index (P <.001). The same result was confirmed performing multivariate analysis in the younger group and centenarians separately. CONCLUSIONS In an older population, the presence of II ACE genotype is associated with a high degree of insulin resistance independent of other anthropometric variables known to interfere with insulin action; this association is significant in both the younger subjects and the centenarians.
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Affiliation(s)
- G Paolisso
- Department of Geriatric Medicine and Metabolic Diseases, Institute of General Pathology and Oncology, Second University of Naples, Italy
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Seidenbecher CI, Langnaese K, Sanmartí-Vila L, Boeckers TM, Smalla KH, Sabel BA, Garner CC, Gundelfinger ED, Kreutz MR. Caldendrin, a novel neuronal calcium-binding protein confined to the somato-dendritic compartment. J Biol Chem 1998; 273:21324-31. [PMID: 9694893 DOI: 10.1074/jbc.273.33.21324] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Using antibodies against synaptic protein preparations, we cloned the cDNA of a new Ca2+-binding protein. Its C-terminal portion displays significant similarity with calmodulin and contains two EF-hand motifs. The corresponding mRNA is highly expressed in rat brain, primarily in cerebral cortex, hippocampus, and cerebellum; its expression appears to be restricted to neurons. Transcript levels increase during postnatal development. A recombinant C-terminal protein fragment binds Ca2+ as indicated by a Ca2+-induced mobility shift in SDS-polyacrylamide gel electrophoresis. Antisera generated against the bacterial fusion protein recognize a brain-specific protein doublet with apparent molecular masses of 33 and 36 kDa. These data are confirmed by in vitro translation, which generates a single 36-kDa polypeptide, and by the heterologous expression in 293 cells, which yields a 33/36-kDa doublet comparable to that found in brain. On two-dimensional gels, the 33-kDa band separates into a chain of spots plausibly due to differential phosphorylation. This view is supported by in situ phosphorylation studies in hippocampal slices. Most of the immunoreactivity is detectable in cytoskeletal preparations with a further enrichment in the synapse-associated cytomatrix. These biochemical data, together with the ultra-structural localization in dendrites and the postsynaptic density, strongly suggest an association with the somato-dendritic cytoskeleton. Therefore, this novel Ca2+-binding protein was named caldendrin.
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Affiliation(s)
- C I Seidenbecher
- AG Molecular and Cellular Neurobiology, Institute for Medical Psychology, Otto-von-Guericke-University, 39120 Magdeburg, Germany
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Wang J, Miller JC, Friedhoff AJ. Differential regulation of D2 receptor gene expression by transcription factor AP-1 in cultured cells. J Neurosci Res 1997; 50:23-31. [PMID: 9379490 DOI: 10.1002/(sici)1097-4547(19971001)50:1<23::aid-jnr3>3.0.co;2-n] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The role of the transcription factor AP-1 in regulating D2 receptor transcriptional activity was investigated in D2 receptor expressing neuroblastoma cells, NB41A3, and in non-D2 receptor expressing CHO cells. Deletion of a region containing the putative AP-1 binding site resulted in a significant reduction in the activity in CHO cells; while the activity in NB41A3 cells was increased suggesting that the AP-1 site may differentially regulate D2 gene expression in these distinct cell types. However, both cell lines were found to express significant and similar levels of the transcription factors AP-1. Analysis of phosphorylated proteins in each of the cell lines provided evidence that AP-1 is phosphorylated in NB41A3 cells, but not in CHO cells. This result suggests that differential regulation of D2 gene expression may be related to AP-1 phosphorylation.
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Affiliation(s)
- J Wang
- Milahuser Laboratories, New York University School of Medicine, New York, USA.
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Aggarwal SR, Palmer TN. Recovery from acute challenge with noradrenaline, vasopressin and angiotensin II in isolated rat hepatocytes. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1310:284-92. [PMID: 8599606 DOI: 10.1016/0167-4889(95)00174-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have previously established that the eleven cytosolic peptides phosphorylated in response to acute glucagon challenge in isolated rat hepatocytes undergo rapid dephosphorylation following transfer to medium free of 32PO4(3-). This dephosphorylation, far from being a simple process, is complex and asynchronous. This novel finding of asynchrony raises the question of whether, by analogy to glucagon, protein dephosphorylation is asynchronous during the recovery phase from acute challenge with noradrenaline, vasopressin or angiotensin II. One-dimensional SDS-PAGE of hepatocyte extracts indicates that noradrenaline stimulates the phosphorylation of ten cytosolic peptides, whereas vasopressin and angiotensin II stimulate the phosphorylation of six cytosolic peptides. Transfer of the hormone-challenged hepatocytes to medium devoid of 32PO4(3-) and hormone led to the rapid net dephosphorylation of the 32P-labelled phosphopeptides, albeit at different rates. In all instances, the most rapidly dephosphorylated phosphopeptide was glycogen phosphorylase. Statistical analysis indicates that during recovery from noradrenaline challenge three distinct groups of phosphopeptides can be delineated on the basis of their rates of dephosphorylation. Despite the fact that vasopressin and angiotensin II stimulate the phosphorylation of the same sub-set of phosphopeptides, there were differences in the rates of dephosphorylation of these phosphopeptides during the recovery phase from acute hormonal challenge.
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Affiliation(s)
- S R Aggarwal
- Department of Biochemistry, University of Western Australia, Nedlands, Australia
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16
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Aggarwal SR, Lindros KO, Palmer TN. Glucagon stimulates phosphorylation of different peptides in isolated periportal and perivenous hepatocytes. FEBS Lett 1995; 377:439-43. [PMID: 8549772 DOI: 10.1016/0014-5793(95)01387-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The perivenous and periportal zones of the liver acinus differ in enzyme complements and capacities for gluconeogenesis, glycolysis and other metabolic processes. The biochemical factors governing this metabolic zonation are still poorly understood. Glucagon-mediated protein phosphorylation is an important factor in the regulation of hepatic metabolism. Here we show, by comparing the 32P-labelling pattern of isolated periportal and perivenous hepatocytes, that glucagon promotes the phosphorylation of zone-specific peptides as well as three common peptides (glycogen phosphorylase, glycogen synthase and pyruvate kinase) in the two cell types. We propose that the zone-specific phosphorylation of peptides is an important factor governing the shortterm zonation of metabolic processes in the liver.
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Affiliation(s)
- S R Aggarwal
- Department of Biochemistry, University of Western Australia, Nedlands, Australia
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Mellgren G, Vintermyr OK, Døskeland SO. Okadaic acid, cAMP, and selected nutrients inhibit hepatocyte proliferation at different stages in G1: modulation of the cAMP effect by phosphatase inhibitors and nutrients. J Cell Physiol 1995; 163:232-40. [PMID: 7706367 DOI: 10.1002/jcp.1041630203] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The protein phosphatase inhibitor okadaic acid (> 100 nM) caused an abrupt and complete cessation of primary rat hepatocyte cell cycle progression at the restriction point in late G1. A decline in the G1/S transition rate was observed in response to elevated cAMP, excess selected nutrients, and okadaic acid (< 100 nM). Excess nutrients (40 mM glucose +/- 5 mM dihydroxyacetone) acted by imposing an incomplete block in early G1. The cAMP action was potentiated by the phosphatase inhibitor microcystin, which in itself did not affect DNA replication. This suggests that cAMP acted by phosphorylating substrate(s) that is dephosphorylated by a microcystin-sensitive phosphatase. The additive effects of submaximal concentrations of okadaic acid and cAMP analogs indicated that okadaic acid and cAMP acted via different pathways. In conclusion, okadaic acid, cAMP, and excess nutrients, acting through distinct pathways, inhibited hepatocytes in different parts of the G1 phase.
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Affiliation(s)
- G Mellgren
- Department of Anatomy and Cell Biology, Medical School, University of Bergen, Norway
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Ayame H, Matsutani A, Inoue H, Kaneko T, Kaku K. Tolbutamide inhibits glucagon-induced phosphorylation of 6PF-2-K/Fru-2,6-P2ase in rat hepatocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1995; 268:E391-6. [PMID: 7900785 DOI: 10.1152/ajpendo.1995.268.3.e391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In previous studies, we demonstrated that tolbutamide inhibits a phosphorylation of hepatic 6-phosphofructo-2-kinase (6PF-2-K)/fructose-2,6-bisphosphatase (Fru-2,6-P2ase) catalyzed by the adenosine 3',5'-cyclic monophosphate-dependent protein kinase in a reconstruction system using the purified enzyme from the rat liver. In the current study, to assess a role of tolbutamide on hepatic 6PF-2-K/Fru-2,6-P2ase physiologically, we used intact rat hepatocytes and examined effects of tolbutamide on a phosphorylation of the bifunctional enzyme in the presence of glucagon. Glucagon induced a rapid phosphorylation of hepatic 6PF-2-K/Fru-2,6-P2ase accompanied by an inhibition of 6PF-2-K activity and a stimulation of Fru-2,6-P2ase activity in a dose-dependent manner. Tolbutamide inhibited glucagon-induced phosphorylation of the bifunctional enzyme protein in a dose-dependent manner. By adding 2 mM tolbutamide, reduced activity of 6PF-2-K and increased activity of Fru-2,6-P2ase in the presence of 10(-9) M glucagon were partially restored. The present results suggest the possibility that tolbutamide modulates the activity of hepatic 6PF-2-K/Fru-2,6-P2ase through inhibiting a phosphorylation of the enzyme protein. The counterregulatory influence of tolbutamide on the effect of glucagon suggests a possible mechanism for the extrapancreatic effect of sulfonylurea drugs.
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Affiliation(s)
- H Ayame
- Third Department of Medicine, Yamaguchi University School of Medicine, Japan
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19
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Aggarwal SR, Palmer TN. Recovery from acute glucagon challenge in isolated rat hepatocytes: is protein dephosphorylation synchronous or asynchronous? BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1224:311-22. [PMID: 7981247 DOI: 10.1016/0167-4889(94)90205-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
One-dimensional SDS-PAGE of cytosolic phosphopeptides confirms that glucagon promotes the phosphorylation of 11 phosphopeptides in isolated rat hepatocytes pre-equilibrated with 32PO4(3-). Nine of these phosphopeptides are tentatively identified, whereas two phosphopeptides (48 kDa and 46 kDa) remain unidentified. Transfer of the glucagon-challenged hepatocytes to medium free of 32PO4(3-) and glucagon led to the rapid net dephosphorylation of the phosphopeptides and to a rapid decline in the specific radioactivity of the [32P]ATP pool. There were profound differences between the post-glucagon rates of net dephosphorylation of the different hepatic phosphopeptides, consistent with net dephosphorylation being asynchronous during the recovery phase from acute glucagon challenge. On the basis of descending rates of dephosphorylation, four major groups of phosphopeptides were delineated. Okadaic acid, a potent inhibitor of protein phosphatase 2A and to a lesser extent protein phosphatase 1, inhibited the dephosphorylation of all of the phosphopeptides. A role for protein phosphatase 2A in protein dephosphorylation may be indicated by the observation that spermine, a specific activator of protein phosphatase 2A, stimulates the dephosphorylation of some, but not all, of the glucagon-stimulated phosphopeptides. Although phosphorylation during the recovery phase from glucagon challenge may be a complicating factor, the results suggest that post-glucagon dephosphorylation is a complex asynchronous process. The physiological consequences of this asynchrony may be that the suppression of glycogenolysis and gluconeogenesis and the activation of glycolysis are early events in the recovery process.
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Affiliation(s)
- S R Aggarwal
- Department of Biochemistry, University of Western Australia, Nedlands
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20
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21
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Mokashi S, Severson DL, Hollenberg MD. Synergistic actions of epidermal growth factor-urogastrone and vasopressin in cultured aortic A-10 smooth muscle cells. J Cell Physiol 1992; 152:372-81. [PMID: 1386368 DOI: 10.1002/jcp.1041520219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In cultured rat aorta-derived A-10 cells, epidermal growth factor-urogastrone (EGF-URO) acts synergistically with arginine vasopressin (AVP) to augment the AVP-mediated release of 3H-arachidonate (3H-AA) from 3H-AA prelabeled cells. On its own, EGF-URO had no effect on AA release and had no effect on calcium influx or efflux either in the absence or presence of AVP. The synergistic action of EGF-URO was not affected by actinomycin D, cycloheximide, indomethacin, by the diacylglycerol lipase inhibitor U-57,908, or by the tyrosine kinase inhibitors genistein (GS) and tyrphostin (TP). TP did, nonetheless, completely abrogate 3H-thymidine incorporation triggered in the presence of EGF-URO. Although EGF-URO stimulated an increase in calpactin-II (lipocortin-I) phosphorylation in permeabilized cells, no such increase was detected in intact cells exposed to EGF-URO either alone or in combination with AVP, under conditions where EGF-URO augmented the action of AVP. The phospholipase A2 inhibitor, mepacrine, had no effect on AVP-mediated AA release, but abolished the synergistic action of EGF-URO. We conclude that in contrast with our previous results with gastric smooth muscle strips, wherein EGF-URO acts via the diacylglycerol lipase-mediated metabolism of diacylglycerol, and in keeping with observations with cultured mesangial cells, EGF-URO acts synergistically with AVP in A-10 cells via the activation of phospholipase A2. This synergistic action of EGF-URO does not appear to be due to increased levels of cyclooxygenase and would appear not to require increased tyrosine kinase activity.
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Affiliation(s)
- S Mokashi
- Department of Pharmacology and Therapeutics, University of Calgary, Faculty of Medicine, Alberta, Canada
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22
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Ding J, Clarke N, Nagai T, Moor RM. Protein and nuclear changes in pig eggs at fertilization. Mol Reprod Dev 1992; 31:287-96. [PMID: 1571162 DOI: 10.1002/mrd.1080310410] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The nuclear restructuring that occurs between insemination and full pronuclear formation in pig eggs is accompanied by posttranslational changes to specific egg proteins. Sperm penetration begins in vitro at 3 hr postinsemination (hpi). By 5 hr, decondensing sperm heads and anaphase II plates are observed in 50% of eggs, and, by 8 hpi, both male and female pronuclei have formed. Three consistent changes to the pattern of newly synthesised proteins are triggered in this period; they affect the 46K, 25K, and 22K polypeptides. Changes are also triggered in the 180-200K polypeptides and in the 14K polypeptides, but these are highly variable. The same changes in the prefertilization pattern were observed when prelabelled eggs were used and new protein synthesis was suppressed. The first and most abrupt change involves the apparent catabolic elimination of a group of 46K unphosphorylated polypeptides (pl 7.3-6.4), whose synthesis was greatest before germinal vesicle breakdown but declined slowly in the final phase of maturation, then declined precipitously after activation. Ageing (beyond maturation) also leads to the disappearance of these polypeptides. The progressive disappearance of a set of 25K polypeptides and the concomitant appearance of a dominant 22K polypeptide is the most characteristic fertilization-induced modification to porcine egg proteins. These modifications begin within 1 hr of sperm penetration or activation, are specific to the pig, and involve heavily phosphorylated polypeptides (25K, pl 6.7-6.0) whose synthesis is begun in the early metaphase I stage. Dual ([35S] and [32P]) labelling, protein blocking experiments, and use of alkaline phosphatase suggest that dephosphorylation selectively affects these 25K polypeptides and is mainly or wholly responsible for converting them (completely within 6 hr) to a single, new (22K, pl 7.6) species that is positively charged. The 25K/22K polypeptide modification has a close temporal relationship with the formation of the male and female pronuclei.
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Affiliation(s)
- J Ding
- Department of Molecular Embryology, AFRC Institute of Animal Physiology and Genetics Research, Babraham, Cambridge, England
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23
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Haynes RC, Picking RA. The role of inhibition of pyruvate kinase in the stimulation of gluconeogenesis by glucagon: a reevaluation. Arch Biochem Biophys 1990; 283:51-9. [PMID: 2173491 DOI: 10.1016/0003-9861(90)90611-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have reexamined the concept that glucagon controls gluconeogenesis from lactate-pyruvate in isolated rat hepatocytes almost entirely by inhibition of flux through pyruvate kinase, thereby making gluconeogenesis more efficient. 1. We tested and refined the 14C-tracer technique that has previously yielded the opposite conclusion, that is, that inhibition of pyruvate kinase is a relatively unimportant mechanism. The tracer procedure, as used by us, was found to be insensitive to the size of the pyruvate pool, and experiments using modifications of the technique to obviate a number of other potential errors support the earlier conclusion that control of pyruvate kinase is not the predominant mechanism. 2. Any stimulation of formation of glucose that results from inhibition of pyruvate kinase is the consequence of elevation of the steady-state concentrations of phosphoenolpyruvate and all subsequent intermediates in the gluconeogenic pathway. During ongoing stimulation of glucose synthesis by glucagon in isolated hepatocytes, the concentrations of all measured intermediate compounds between phosphoenolpyruvate and glucose were elevated except triose phosphates and fructose 1,6-bisphosphate. The failure of these compounds to rise above control levels indicates that not all gluconeogenic reactions beyond pyruvate kinase were accelerated thermodynamically as would occur with predominant control at pyruvate kinase. We conclude, therefore, that although glucagon inhibits flux through the pyruvate kinase reaction, this does not account for most of the stimulation of gluconeogenesis. Major control sites are also within the pyruvate-phosphoenolpyruvate segment and the fructose 1,6-bisphosphate cycle.
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Affiliation(s)
- R C Haynes
- Department of Pharmacology, University of Virginia, Charlottesville 22908
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24
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Forte JG, Hanzel DK, Okamoto C, Chow D, Urushidani T. Membrane and protein recycling associated with gastric HCl secretion. JOURNAL OF INTERNAL MEDICINE. SUPPLEMENT 1990; 732:17-26. [PMID: 2166524 DOI: 10.1111/j.1365-2796.1990.tb01467.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Stimulation of the gastric parietal cell requires massive membrane transformations as H(+)-pumps from the domain of cytoplasmic tubulovesicles are recruited into the apical plasma membrane domain. The recycling of membrane pools, through fusion and fission processes that accompany stimulation and inhibition of HCl secretion, also involves highly selective events of protein incorporation and segregation. This manuscript describes several proteins that have been identified with the apical plasma membrane from maximally stimulated parietal cells, and broadly characterizes them either as permanent resident proteins of the apical membrane, or transient proteins that move into and out of the apical membrane as the cell progresses through the secretory cycle. A typical example of transient association with the apical membrane concerns the pump proteins, including the 94 kDa catalytic alpha-subunit of the H+K(+)-ATPase and its newly discovered beta-subunit glycoprotein, which move between tubulovesicles. Proteins that remain associated with the apical plasma membrane during rest and secretion include actin, and an 80-kDa phosphoprotein, which has been variously called 80 K, ezrin, p81 and cytovillin, and whose phosphorylation is increased by the histamine/cAMP pathway of parietal cell stimulation. An example of a cytosolic protein that becomes associated with the apical plasma membrane after stimulation is a 120-kDa protein, which appears to have protein kinase activity. Note that the identification, localization and characterization of the K+ and Cl- transport proteins, which participate in net HCl secretion, are of immediate importance.
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Affiliation(s)
- J G Forte
- Department of Molecular and Cell Biology, University of California, Berkeley
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25
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Granot Y, Van Putten V, Schrier RW. Vasopressin dependent tyrosine phosphorylation of a 38 kDa protein in human platelets. Biochem Biophys Res Commun 1990; 168:566-73. [PMID: 1692212 DOI: 10.1016/0006-291x(90)92358-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Arginine vasopressin administration (10(-10)-10(-6) M) to isolated human platelets induces an increase in the specific immunoblotting of a 38 kDa protein revealed by a phosphotyrosine antibody. This signal is biphasic with maximal stimulation within one minute. Neither forskolin (10(-5) M) nor phorbol ester (10(-6) M) produces a similar 38 kDa signal. The specific immunoblotted signals are competitively abolished by 1 mM phosphotyrosine but not phosphoserine or phosphothreonine. Electrophoretic separation at pH 3.5 of the acid hydrolysates of the 38 kDa proteins reveals a vasopressin dependent increase in levels of phosphotyrosine as well as phosphoserine and phosphothreonine. The 38 kDa phosphorylation is also induced by the specific arginine vasopressin V1 receptor agonist (Phe2Orn8Vastocina) and blocked by the V1 receptor antagonist [desGly(NH2)d(CH2)5Tyr(Me) AVPb]. These observations suggest that arginine vasopressin signal transduction may be associated with the tyrosine phosphorylation of a 38 kDa protein.
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Affiliation(s)
- Y Granot
- Department of Medicine, University of Colorado School of Medicine, Denver 80262
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26
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Yamaguchi M, Mori S. Inhibitory effect of calcium-binding protein regucalcin on protein kinase C activity in rat liver cytosol. BIOCHEMICAL MEDICINE AND METABOLIC BIOLOGY 1990; 43:140-6. [PMID: 2346670 DOI: 10.1016/0885-4505(90)90019-w] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Regucalcin, a calcium-binding protein isolated from rat liver cytosol, inhibited Ca2(+)- and phospholipid-dependent protein kinase (protein kinase C) activity in hepatic cytosol. With the increasing concentrations of Ca2+ or phosphatidylserine in the medium, regucalcin caused a remarkable inhibition of protein kinase C activity. Moreover, regucalcin significantly inhibited dioctanoylglycerol-activated protein kinase C. Regucalcin itself did not have protein kinase activity in either the presence or the absence of Ca2+ and phospholipids. These findings clearly indicate that regucalcin has an inhibitory effect on protein kinase C in hepatic cytosol. This inhibitory effect of regucalcin may be due to the regucalcin-induced Ca2+ binding and/or the direct binding of regucalcin to protein kinase C.
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Affiliation(s)
- M Yamaguchi
- Department of Environmental Biochemistry, School of Pharmaceutical Sciences, University of Shizuoka, Japan
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27
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Ben-Ari ET, Lynch KR, Garrison JC. Glucocorticoids Induce the Accumulation of Novel Angiotensinogen Gene Transcripts. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)51597-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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28
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Abstract
Three methods for calculating the isoelectric points (pI) of proteins, provided that their amino acid compositions are known, are described. The comprehensive and abridged procedures involve solutions of polynomial equations of different degrees depending on whether pK values of the specific acid-base residues or the means of some of those values, respectively, are adopted. In the simplified procedure, approximate pI values of proteins can be determined easily with the help of calculated values, included in this paper, related to the amino acid composition of proteins.
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Affiliation(s)
- A Sillero
- Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Medicina, Universidad de Extremadura, Badajoz, Spain
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29
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Phosphorylation Modulates the Activity of Glycine N-Methyltransferase, a Folate Binding Protein. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)60578-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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30
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Thiel G, Söling HD. cAMP-dependent protein phosphorylation of membrane proteins in the parotid gland, platelets and liver. Comparison of a 22-kDa phosphoprotein from rat parotid microsomes (protein III) with phosphoproteins of similar molecular size from platelet and liver membranes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1988; 174:601-9. [PMID: 3391174 DOI: 10.1111/j.1432-1033.1988.tb14141.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Stimulation of secretion in exocrine secretory glands leads to the phosphorylation of a 22-kDa membrane protein (protein III) whose function is still unknown [Jahn et al. (1980) Eur. J. Biochem. 112, 345-352; Jahn & Söling (1980) Proc. Natl Acad. Sci. USA 78, 6903-6906]. This report describes the comparison of this protein with phosphorylated membrane proteins of similar molecular mass in platelets and liver. Incubation of platelets with agents which raise the intracellular cAMP concentration results in the phosphorylation of a 22-kDa protein which is also phosphorylated in membrane preparations by endogenous kinases or by exogenous cAMP-dependent protein kinase. It is shown that this protein is distinct from protein III although both proteins have the same molecular mass and are substrates of cAMP-dependent protein kinase. In contrast to platelets, protein III could be demonstrated in liver microsomes. This indicates that the function of protein III is not exclusively linked to the stimulus-secretion coupling in exocrine cells.
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Affiliation(s)
- G Thiel
- Abteilung Klinische Biochemie, Zentrum Innere Medizin, Universität Göttingen
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31
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O'Reilly MA, Gazdar AF, Morris RE, Whitsett JA. Differential effects of glucocorticoid on expression of surfactant proteins in a human lung adenocarcinoma cell line. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 970:194-204. [PMID: 3382698 DOI: 10.1016/0167-4889(88)90179-6] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Synthesis of pulmonary surfactant-associated glycoproteins of Mr 28,000-36,000 (SP-A) and Mr 42,000-46,000 (proSP-B) has been identified in a continuous cell line derived from a human lung adenocarcinoma. SP-A was detected by immunoblot analysis, ELISA assay and by [35S]methionine labelling of the cells. SP-A was secreted into the media as an endoglycosidase F sensitive glycoprotein which co-migrated with the isoforms of SP-A identified in human lavage fluid by 2D-IEF-SDS-PAGE. Hybridization of cellular RNA with SP-A-specific cDNA identified an abundant 2.2 kb mRNA species, identical to that observed in human lung. SP-A RNA and protein content were markedly inhibited by dexamethasone in a dose-dependent fashion. Under identical culture conditions, synthesis of a distinct surfactant protein, SP-B, was markedly stimulated by the glucocorticoid. The SP-B precursor was secreted into the media as heterogeneous Mr 42,000-46,000 protein, pI 4.6-5.1, and was sensitive to endoglycosidase F. Synthesis of proSP-B was enhanced by the glucocorticoid in a dose-dependent fashion and was associated with increased SP-B mRNA of 2.0 kb detected by Northern blot analysis. The cell line secreted proSP-B as Mr 42,000-46,000 glycosylated protein and did not process the precursor to the Mr 7000-8000 surfactant peptide. In summary, a human adenocarcinoma cell line has been identified which synthesizes and secretes two surfactant-associated proteins, SP-A and proSP-B. Glucocorticoid enhanced SP-B but inhibited SP-A expression in this cell line. The identification of a continuous cell line secreting surfactant proteins may be useful in the study of synthesis and secretion of these important proteins and for production of the proteins for clinical uses.
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Affiliation(s)
- M A O'Reilly
- University of Cincinnati College of Medicine, Department of Pediatrics, OH 45267-0541
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32
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Bandyopadhyay SK, Rosenberg E, Kiron MA, Soffer RL. Purification and properties of an angiotensin-binding protein from rabbit liver particles. Arch Biochem Biophys 1988; 263:272-80. [PMID: 3132105 DOI: 10.1016/0003-9861(88)90636-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
An angiotensin II-binding protein was purified more than 8000-fold after solubilization from rabbit liver particles with digitonin. The procedure comprised fractionation with ammonium sulfate, chromatography on DEAE-cellulose and Affi-Gel 501, gel filtration through Sephacryl S-200, and chromatography with hydroxylapatite. The purified preparation exhibited Kd and Bmax values of 6.7 nM and 8.4 nmol of angiotensin II bound/mg protein. The latter figure represents more than 60% of the theoretical value calculated for a protein of Mr 75,000 as estimated for the major protein component by gel electrophoresis. The purified preparation displayed comparable or slightly higher affinities for various angiotensin antagonists and angiotensin III than that for angiotensin II, whereas angiotensin I as well as the hexapeptide and smaller carboxy-terminal fragments were less tightly bound. Binding of angiotensin II by the isolated protein was highly dependent upon the presence of p-chloromercuriphenylsulfonic acid and also required ethylene diaminetetraacetic acid which could be almost completely replaced by ethylene glycol bis(beta-aminoethyl ether) N,N'-tetraacetic acid but not by o-phenanthroline.
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Affiliation(s)
- S K Bandyopadhyay
- Department of Biochemistry, Cornell University Medical College, New York, New York 10021
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33
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O'Reilly MA, Nogee L, Whitsett JA. Requirement of the collagenous domain for carbohydrate processing and secretion of a surfactant protein, SP-A. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 969:176-84. [PMID: 3355864 DOI: 10.1016/0167-4889(88)90073-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Two distinct intracellular forms of surfactant protein Mr = 35,000 (SP-A) were demonstrated in both purified type II epithelial cells and rat lung in vivo. High-mannose precursors of Mr = 30,000 and 34,000 comprised a significant fraction of intracellular SP-A in vivo and in vitro. A second intracellular pool was demonstrated in lamellar body enriched fractions, which contained endoglycosidase-H resistant, sialylated forms of SP-A. Intracellular transport and secretion of SP-A was not altered by inhibitors of carbohydrate processing. However, incubation of type II cells with alpha,alpha'-dipyridyl or cis-4-hydroxy-L-proline, agents which disrupt triple-helix formation within collagenous peptide domains, inhibited sialylation, intracellular transport to the lamellar body fraction and secretion. In the presence of either alpha,alpha'-dipyridyl or cis-4-hydroxy-L-proline, high mannose precursors accumulated intracellularly and were not secreted after 16-18 h. Thus, high-mannose precursors in proximal intracellular pool(s) and sialylated forms in lamellar body-enriched fractions represent two major intracellular storage forms of SP-A in vitro and in vivo. SP-A is routed by processes dependent upon the hydroxylation of the collagenous domain of the polypeptide. Transport and secretion of SP-A are not dependent upon the addition or processing of asparagine-linked carbohydrate.
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Affiliation(s)
- M A O'Reilly
- University of Cincinnati, College of Medicine, Department of Pediatrics, OH 45267-0541
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34
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Glucocorticoid enhances surfactant proteolipid Phe and pVal synthesis and RNA in fetal lung. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47771-x] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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35
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Weaver TE, Kropp KL, Whitsett JA. In vitro sulfation of pulmonary surfactant-associated protein-35. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 914:205-11. [PMID: 3607072 DOI: 10.1016/0167-4838(87)90065-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Surfactant-associated protein-35 consists of a group of phospholipid-associated proteins of 26-36 kDa isolated from pulmonary alveolar surfactant. In the rat, surfactant-associated protein-35 is synthesized from 26-kDa primary translation products which are cotranslationally acetylated and glycosylated to heterogeneous 30 and 34 kDa forms. High-mannose oligosaccharide-containing precursors of surfactant-associated protein-35 are processed in the rough endoplasmic reticulum and Golgi to complex-type oligosaccharides, resulting in a mature glycoprotein which exhibits extensive charge heterogeneity in two-dimensional isoelectric focusing SDS-polyacrylamide gel electrophoresis. Much of this charge heterogeneity is related to terminal sialylation of the two asparagine-linked oligosaccharides. In the present study, we report that surfactant-associated protein-35 is also sulfated. Sulfation of the 30 and 34 kDa forms of surfactant-associated protein-35 was clearly detected in primary cultures of rat Type II epithelial cells. These sulfated isoforms were sensitive to endoglycosidase F digestion, but resistant to neuraminidase, suggesting that sulfation occurred at oligosaccharide residues other than sialic acid. The lack of sulfation of the 26 kDa forms of surfactant-associated protein-35 and the resistance of the sulfated isoforms to endoglycosidase H digestion are consistent with Golgi-associated sulfation of the complex type oligosaccharides of surfactant-associated protein-35. Thus, sulfation is another component of the complex post-translational processing of surfactant-associated protein-35, which includes acetylation, hydroxylation, glycosylation, sialylation, sulfhydryl-dependent oligomerization and sulfation.
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36
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Evidence for the activation of the multifunctional Ca2+/calmodulin-dependent protein kinase in response to hormones that increase intracellular Ca2+. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61091-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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37
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Hsu YC, Bloxham DP, Giles IG. Phosphorylation of type-L pyruvate kinase in intact hepatocytes. Localisation of the phosphorylation site in response to both glucagon and the Ca2+-linked agonist phenylephrine. FEBS Lett 1987; 218:1-6. [PMID: 3036585 DOI: 10.1016/0014-5793(87)81006-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Pyruvate kinase is one of the enzymes which can be phosphorylated by stimulation of the cell with either glucagon or Ca2+-linked hormones. Whether these two classes of hormones phosphorylate the same site on the enzyme is unclear. Our results demonstrate that isolation of [32P]phosphorylated type-L pyruvate kinase from glucagon-treated hepatocytes followed by aspartyl-prolyl cleavage yields a [32P]phosphorylated peptide of Mr 17,000. This fragment is also phosphorylated in response to the Ca2+-mediated agonist phenylephrine.
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38
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Differential effects of epidermal growth factor and transforming growth factor-beta on synthesis of Mr = 35,000 surfactant-associated protein in fetal lung. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47654-5] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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39
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Whitsett J, Pilot T, Clark J, Weaver T. Induction of surfactant protein in fetal lung. Effects of cAMP and dexamethasone on SAP-35 RNA and synthesis. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61182-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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40
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Connelly P, Botelho L, Sisk R, Garrison J. A study of the mechanism of glucagon-induced protein phosphorylation in isolated rat hepatocytes using (Sp)-cAMPS and (Rp)-cAMPS, the stimulatory and inhibitory diastereomers of adenosine cyclic 3',5'-phosphorothioate. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61351-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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41
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Ross GF, Ohning BL, Tannenbaum D, Whitsett JA. Structural relationships of the major glycoproteins from human alveolar proteinosis surfactant. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 911:294-305. [PMID: 3101739 DOI: 10.1016/0167-4838(87)90070-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Alveolar proteinosis is a disease characterized by accumulation of proteinaceous material in the alveolar space of the lung. Two major collagenase-sensitive polypeptides, alveolar proteinosis peptides of 34 kDa kilodaltons (APP-34) and of 62 kDa (APP-62), were isolated from bronchioalveolar lavage of patients with alveolar proteinosis. These proteins co-purified during fast-performance liquid chromatography (FPLC) chromatofocusing and were separated from each other by electroelution following SDS-polyacrylamide gel electrophoresis. Immunoblot analysis of these proteins demonstrated that both shared antigenic sites with the normal human surfactant-associated protein of Mr 34,000 (SAP-34) using both polyclonal and monoclonal antibodies generated against SAP-34. Removal of asparagine-linked oligosaccharides from the 34 kDa and 62 kDa alveolar proteinosis proteins with endoglycosidase F resulted in polypeptides of 28 kDa from APP-34 and 56 kDa from APP-62. Amino acid analysis and tryptic peptide maps of the electroeluted APP-34 and APP-62 proteins were essentially identical and similar to that previously reported for human SAP-34, supporting the likely relationship of APP-34 and APP-62 as monomer and dimer of the normal SAP-34. APP-34 and APP-62 were both sensitive to bacterial collagenase, yielding collagenase-resistant fragments of 21 kDa, similar in migration and amino acid composition to the fragment generated by collagenase digestion of normal human SAP-34. High molecular weight aggregates of APP-34 and APP-62 were the result of sulfhydryl-dependent and non-sulfhydryl-dependent cross-linking. A domain in the C-terminal non-collagenous portion of the molecules which forms sulfhydryl-dependent oligomers was identified. The two major polypeptides accumulating in the airway of patients with alveolar proteinosis are monomeric (34 kDa) and dimeric (62 kDa) forms of the major surfactant-associated glycoprotein, SAP-34.
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42
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2 Pyruvate Kinase. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/s1874-6047(08)60253-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Pilkis SJ, Claus TH, Kountz PD, El-Maghrabi MR. 1 Enzymes of the Fructose 6-Phosphate-Fructose 1, 6-Bisphosphate Substrate Cycle. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/s1874-6047(08)60252-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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44
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Kaufman S. 8 Aromatic Amino Acid Hydroxylases. ACTA ACUST UNITED AC 1987. [DOI: 10.1016/s1874-6047(08)60259-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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45
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Deviller P, Vallier P, Saez JM. Corticotropin and angiotensin induce dephosphorylation of a Mr-20,000 protein in bovine adrenal cells. Endocr Res 1987; 13:123-42. [PMID: 3040386 DOI: 10.3109/07435808709023668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
ACTH (1-24) and Angiotensin II, both able to activate steroidogenesis in bovine fasciculata-reticularis cells, each reduced the [32P] incorporation in a cytosolic Mr-20,000 pI 6.8 protein in this cell. Cells preincubated with Sar1-Angiotensin prevented the effect of Angiotensin. Angiotensin 10(-8)M and ACTH 10(-10)M led to an almost complete disappearance of the corresponding radioactive spot on the autoradiograph. The effect was observed as soon as 2 minutes after addition of hormones to the cells. Other activators of steroidogenesis such as 8-bromocyclicAMP (8-BrcAMP), 4 beta-Phorbol-12 beta-Myristate-13 alpha-acetate (PMA) and [9-tryptophan (o-nitrophenylsulfenyl)] substituted ACTH (NPS-ACTH), also reduced the labeling of the Mr-20,000 polypeptide. On the other hand, this effect was not reproduced by insulin or human growth hormone (hGH). On 2-D gels from control, the coincidence of this polypeptide with phosphorylated myosin light chain was not observed. We suggest that the apparent dephosphorylation of this polypeptide may represent a common effect of all steroidogenic agents regardless of their seemingly distinct early actions.
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Pilkis SJ, Fox E, Wolfe L, Rothbarth L, Colosia A, Stewart HB, el-Maghrabi MR. Hormonal modulation of key hepatic regulatory enzymes in the gluconeogenic/glycolytic pathway. Ann N Y Acad Sci 1986; 478:1-19. [PMID: 2879498 DOI: 10.1111/j.1749-6632.1986.tb15517.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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47
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Ross GF, Notter RH, Meuth J, Whitsett JA. Phospholipid binding and biophysical activity of pulmonary surfactant-associated protein (SAP)-35 and its non-collagenous COOH-terminal domains. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)67016-4] [Citation(s) in RCA: 69] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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48
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Côté A, Doucet JP, Trifaró JM. Phosphorylation and dephosphorylation of chromaffin cell proteins in response to stimulation. Neuroscience 1986; 19:629-45. [PMID: 3774157 DOI: 10.1016/0306-4522(86)90286-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Stimulation of bovine chromaffin cell in culture changed (increased or decreased) the phosphorylation state of several proteins as examined by 32P incorporation. Enhanced phosphorylation of 22 protein bands as well as increased dephosphorylation of a 20.4 kilodaltons protein band was observed when extracts of cultured chromaffin cells stimulated by either acetylcholine or high K+ were subjected to mono-dimensional gel electrophoresis. For several protein bands, the degree of phosphorylation was larger in cells stimulated by acetylcholine than in those challenged by a depolarizing concentration of K+. The most affected phosphoproteins have apparent molecular weights of 14,800, 29,000, 33,000, 57,000 (tubulin subunit), 63,000 (tyrosine hydroxylase subunit) and 94,000. The presence of a low extracellular calcium concentration (0.5 mM Ca2+ plus 15 mM Mg2+) in the incubation medium inhibited (38-100%) the acetylcholine-evoked increases in protein phosphorylation observed previously for 18 protein bands. Trifluoperazine at the concentration required for 50% inhibition of acetylcholine-induced catecholamine release decreases (33-100%) the stimulation-induced phosphorylation in all polypeptides, with the exception of the 14.8 kilodaltons and the dephosphorylated 20.4 kilodaltons components which were not affected. Two-dimensional gel electrophoresis analysis revealed that exposure of chromaffin cells to acetylcholine produced two types of effect on protein phosphorylation: activation of protein kinase activities affecting about 30 polypeptides; activation of protein phosphatase activities resulting in the dephosphorylation of about 40 polypeptides, most of them appearing as minor phosphoproteins, with the exception of the alpha-subunit of pyruvate dehydrogenase and the 20.4 kilodaltons polypeptide. On the basis of their molecular properties (molecular weight and pI) and their abundance in chromaffin cells, the 80 kilodaltons phosphoprotein which focused at pI 4.8 and the 117.5 kilodaltons phosphoprotein which focused at pI 5.0 were identified as chromogranins A and B, respectively. The relationship between acetylcholine-induced protein phosphorylation (or dephosphorylation) and catecholamine secretion was also investigated. The time course of protein phosphorylation (or dephosphorylation) paralleled or preceded [3H]noradrenaline release for 16 phosphoproteins.(ABSTRACT TRUNCATED AT 400 WORDS)
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Soderling TR, Schworer CM, el-Maghrabi MR, Pilkis SJ. Phosphorylation of liver pyruvate kinase by Ca++/calmodulin-dependent protein kinase: characterization of two phosphorylation sites. Biochem Biophys Res Commun 1986; 139:1017-23. [PMID: 3094523 DOI: 10.1016/s0006-291x(86)80279-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Rat liver pyruvate kinase is phosphorylated by calcium/calmodulin-dependent protein kinase II at serine and threonine residues in a 3-4 kDa CNBr fragment located near the amino terminus. The two sites of phosphorylation were separated by reverse-phase HPLC of a thermolysin digest. Sequence analysis established the sites of phosphorylation as follows: Leu-Arg-Arg-Ala-Ser(PO4)-Val-Ala-Gln-Leu-Thr(PO4)-Gln-Glu.
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Fishman JB, Dickey BF, McCrory MF, Fine RE. Reversible inactivation of vasopressin and angiotensin II binding to hepatocyte membranes by a calcium-dependent, cytosolic protein. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)38455-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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