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Lim J, Liu Z, Apontes P, Feng D, Pessin JE, Sauve AA, Angeletti RH, Chi Y. Dual mode action of mangiferin in mouse liver under high fat diet. PLoS One 2014; 9:e90137. [PMID: 24598864 PMCID: PMC3943915 DOI: 10.1371/journal.pone.0090137] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 01/28/2014] [Indexed: 12/31/2022] Open
Abstract
Chronic over-nutrition is a major contributor to the spread of obesity and its related metabolic disorders. Development of therapeutics has been slow compared to the speedy increase in occurrence of these metabolic disorders. We have identified a natural compound, mangiferin (MGF) (a predominant component of the plants of Anemarrhena asphodeloides and Mangifera indica), that can protect against high fat diet (HFD) induced obesity, hyperglycemia, insulin resistance and hyperlipidemia in mice. However, the molecular mechanisms whereby MGF exerts these beneficial effects are unknown. To understand MGF mechanisms of action, we performed unbiased quantitative proteomic analysis of protein profiles in liver of mice fed with HFD utilizing 15N metabolically labeled liver proteins as internal standards. We found that out of 865 quantified proteins 87 of them were significantly differentially regulated by MGF. Among those 87 proteins, 50% of them are involved in two major processes, energy metabolism and biosynthesis of metabolites. Further classification indicated that MGF increased proteins important for mitochondrial biogenesis and oxidative activity including oxoglutarate dehydrogenase E1 (Dhtkd1) and cytochrome c oxidase subunit 6B1 (Cox6b1). Conversely, MGF reduced proteins critical for lipogenesis such as fatty acid stearoyl-CoA desaturase 1 (Scd1) and acetyl-CoA carboxylase 1 (Acac1). These mass spectrometry data were confirmed and validated by western blot assays. Together, data indicate that MGF upregulates proteins pivotal for mitochondrial bioenergetics and downregulates proteins controlling de novo lipogenesis. This novel mode of dual pharmacodynamic actions enables MGF to enhance energy expenditure and inhibit lipogenesis, and thereby correct HFD induced liver steatosis and prevent adiposity. This provides a molecular basis supporting development of MGF or its metabolites into therapeutics to treat metabolic disorders.
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Affiliation(s)
- Jihyeon Lim
- The Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
- Department of Pathology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
- * E-mail: (JL)
| | - Zhongbo Liu
- Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
- * E-mail: (JL)
| | - Pasha Apontes
- Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Daorong Feng
- Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Jeffrey E. Pessin
- Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
- Department of Molecular Pharmacology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Anthony A. Sauve
- Department of Pharmacology, Weill Cornell Medical College, New York, New York, United States of America
| | - Ruth H. Angeletti
- The Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
- Department of Pathology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - Yuling Chi
- Department of Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
- * E-mail: (JL)
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Tarassishin L, Lim J, Weatherly DB, Angeletti RH, Lee SC. Interleukin-1-induced changes in the glioblastoma secretome suggest its role in tumor progression. J Proteomics 2014; 99:152-168. [PMID: 24503185 DOI: 10.1016/j.jprot.2014.01.024] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 01/02/2014] [Accepted: 01/23/2014] [Indexed: 12/26/2022]
Abstract
UNLABELLED The tumor microenvironment including glial cells and their inflammatory products regulates brain tumor development and progression. We have previously established that human glioma cells are exquisitely sensitive to IL-1 stimulation leading us to undertake a comparative analysis of the secretome of unstimulated and cytokine (IL-1)-stimulated glioblastoma cells. We performed label-free quantitative proteomic analysis and detected 190 proteins which included cytokines, chemokines, growth factors, proteases, cell adhesion molecules, extracellular matrix (ECM) and related proteins. Measuring area under the curve (AUC) of peptides for quantitation, the IL-1-induced secretome contained 13 upregulated and 5 downregulated extracellular proteins (p<0.05) compared to controls. Of these, IL-8, CCL2, TNC, Gal-1 and PTX3 were validated as upregulated and SERPINE1, STC2, CTGF and COL4A2 were validated as downregulated factors by immunochemical methods. A major representation of the ECM and related proteins in the glioblastoma secretome and their modulation by IL-1 suggested that IL-1 induces its effect in part by altering TGFβ expression, activity and signaling. These findings enhance our understanding of IL-1-induced modulation of glioma microenvironment, with implications for increased tumor invasion, migration and angiogenesis. They further provide novel targets for the glioblastoma intervention. BIOLOGICAL SIGNIFICANCE Present study is on an unbiased screening of the glioblastoma secretome stimulated by IL-1 which triggers neuroinflammatory cascades in the central nervous system. Network of secreted proteins were shown to be regulated revealing their possible contribution to glioma progression. Label free quantitative proteomics has provided unique novel targets for potential glioblastoma intervention.
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Affiliation(s)
- Leonid Tarassishin
- Department of Pathology, Albert Einstein College of Medicine, Bronx NY 10461
| | - Jihyeon Lim
- Department of Pathology, Albert Einstein College of Medicine, Bronx NY 10461.,Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine, Bronx NY 10461
| | - D Brent Weatherly
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602
| | - Ruth H Angeletti
- Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine, Bronx NY 10461.,Department of Developmental & Molecular Biology, Albert Einstein College of Medicine, Bronx NY 10461
| | - Sunhee C Lee
- Department of Pathology, Albert Einstein College of Medicine, Bronx NY 10461
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Nardelli SC, Che FY, Silmon de Monerri NC, Xiao H, Nieves E, Madrid-Aliste C, Angel SO, Sullivan WJ, Angeletti RH, Kim K, Weiss LM. The histone code of Toxoplasma gondii comprises conserved and unique posttranslational modifications. mBio 2013. [PMID: 24327343 DOI: 10.128/mbio.00922013] [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] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023] Open
Abstract
UNLABELLED Epigenetic gene regulation has emerged as a major mechanism for gene regulation in all eukaryotes. Histones are small, basic proteins that constitute the major protein component of chromatin, and posttranslational modifications (PTM) of histones are essential for epigenetic gene regulation. The different combinations of histone PTM form the histone code for an organism, marking functional units of chromatin that recruit macromolecular complexes that govern chromatin structure and regulate gene expression. To characterize the repertoire of Toxoplasma gondii histone PTM, we enriched histones using standard acid extraction protocols and analyzed them with several complementary middle-down and bottom-up proteomic approaches with the high-resolution Orbitrap mass spectrometer using collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and/or electron transfer dissociation (ETD) fragmentation. We identified 249 peptides with unique combinations of PTM that comprise the T. gondii histone code. T. gondii histones share a high degree of sequence conservation with human histones, and many modifications are conserved between these species. In addition, T. gondii histones have unique modifications not previously identified in other species. Finally, T. gondii histones are modified by succinylation, propionylation, and formylation, recently described histone PTM that have not previously been identified in parasitic protozoa. The characterization of the T. gondii histone code will facilitate in-depth analysis of how epigenetic regulation affects gene expression in pathogenic apicomplexan parasites and identify a new model system for elucidating the biological functions of novel histone PTM. IMPORTANCE Toxoplasma gondii is among the most common parasitic infections in humans. The transition between the different stages of the T. gondii life cycle are essential for parasite virulence and survival. These differentiation events are accompanied by significant changes in gene expression, and the control mechanisms for these transitions have not been elucidated. Important mechanisms that are involved in the control of gene expression are the epigenetic modifications that have been identified in several eukaryotes. T. gondii has a full complement of histone-modifying enzymes, histones, and variants. In this paper, we identify over a hundred PTM and a full repertoire of PTM combinations for T. gondii histones, providing the first large-scale characterization of the T. gondii histone code and an essential initial step for understanding how epigenetic modifications affect gene expression and other processes in this organism.
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Affiliation(s)
- Sheila C Nardelli
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, Bronx, New York, USA
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Abstract
Despite the clinical success of microtubule-interacting agents (MIA), a significant challenge for oncologists is the inability to predict the response of individual patients with cancer to these drugs. In the present study, six cell lines were compared by 2D DIGE proteomics to investigate cellular resistance to the class of MIAs known as microtubule-stabilizing agents (MSA). The human lung cancer cell line A549 was compared with two drug-resistant daughter cell lines, a taxol-resistant cell line (AT12) and an epothilone B (EpoB)-resistant cell line (EpoB40). The ovarian cancer cell line Hey was compared with two drug-resistant daughter cell lines, an EpoB-resistant cell line (EpoB8) and an ixabepilone-resistant cell line (Ixab80). All 2D DIGE results were validated by Western blot analyses. A variety of cytoskeletal and cytoskeleton-associated proteins were differentially expressed in drug-resistant cells. Differential abundance of 14-3-3σ, galectin-1 and phosphorylation of stathmin are worthy of further studies as candidate predictive biomarkers for MSAs. This is especially true for galectin-1, a β-galactose-binding lectin that mediates tumor invasion and metastasis. Galectin-1 was greatly increased in EpoB- and ixabepilone-resistant cells and its suppression caused an increase in drug sensitivity in both drug-sensitive and -resistant Hey cells. Furthermore, the growth medium from resistant Hey cells contained higher levels of galectin-1, suggesting that galectin-1 could play a role in resistance to MSAs.
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Affiliation(s)
- Jakob Albrethsen
- Corresponding Author: Chia-Ping Huang Yang, Department of Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461.
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Berezniuk I, Lyons PJ, Sironi JJ, Xiao H, Setou M, Angeletti RH, Ikegami K, Fricker LD. Cytosolic carboxypeptidase 5 removes α- and γ-linked glutamates from tubulin. J Biol Chem 2013; 288:30445-30453. [PMID: 24022482 DOI: 10.1074/jbc.m113.497917] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cytosolic carboxypeptidase 5 (CCP5) is a member of a subfamily of enzymes that cleave C-terminal and/or side chain amino acids from tubulin. CCP5 was proposed to selectively cleave the branch point of glutamylated tubulin, based on studies involving overexpression of CCP5 in cell lines and detection of tubulin forms with antisera. In the present study, we examined the activity of purified CCP5 toward synthetic peptides as well as soluble α- and β-tubulin and paclitaxel-stabilized microtubules using a combination of antisera and mass spectrometry to detect the products. Mouse CCP5 removes multiple glutamate residues and the branch point glutamate from the side chains of porcine brain α- and β-tubulin. In addition, CCP5 excised C-terminal glutamates from detyrosinated α-tubulin. The enzyme also removed multiple glutamate residues from side chains and C termini of paclitaxel-stabilized microtubules. CCP5 both shortens and removes side chain glutamates from synthetic peptides corresponding to the C-terminal region of β3-tubulin, whereas cytosolic carboxypeptidase 1 shortens the side chain without cleaving the peptides' γ-linked residues. The rate of cleavage of α linkages by CCP5 is considerably slower than that of removal of a single γ-linked glutamate residue. Collectively, our data show that CCP5 functions as a dual-functional deglutamylase cleaving both α- and γ-linked glutamate from tubulin.
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Affiliation(s)
- Iryna Berezniuk
- From the Departments of Molecular Pharmacology and; Neuroscience and
| | | | | | - Hui Xiao
- the Laboratory of Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York 10461 and
| | - Mitsutoshi Setou
- the Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192, Japan
| | - Ruth H Angeletti
- the Laboratory of Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York 10461 and
| | - Koji Ikegami
- the Department of Cell Biology and Anatomy, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu 431-3192, Japan
| | - Lloyd D Fricker
- From the Departments of Molecular Pharmacology and; Neuroscience and.
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Kalyoussef S, Nieves E, Dinerman E, Carpenter C, Shankar V, Oh J, Burd B, Angeletti RH, Buckheit KW, Fredricks DN, Madan RP, Keller MJ, Herold BC. Lactobacillus proteins are associated with the bactericidal activity against E. coli of female genital tract secretions. PLoS One 2012. [PMID: 23185346 PMCID: PMC3501525 DOI: 10.1371/journal.pone.0049506] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Female genital tract secretions are bactericidal for Escherichia (E.) coli ex vivo. However, the intersubject variability and molecules that contribute to this activity have not been defined. METHODS The bactericidal activity and concentration of immune mediators in cervicovaginal lavage (CVL) collected from 99 healthy women were determined. RESULTS CVL reduced the number of E. coli colonies by 68% [-26, 100] (median [range]). CVL were active against laboratory and clinical isolates of E. coli, but were inactive against Lactobacillus species. Bactericidal activity correlated with the concentration of protein recovered (p<0.001), but not with cytokines, chemokines or antimicrobial peptides. Four CVL with>90% inhibitory activity (active) and two with<30% activity were subjected to MS/MS proteomic analysis. 215 proteins were identified and six were found exclusively in active samples. Four of these corresponded to Lactobacillus crispatus or jensenii proteins. Moreover, culture supernatants from Lactobacillus jensenii were bactericidal for E. coli. CONCLUSION Both host and commensal microbiota proteins contribute to mucosal defense. Identification of these proteins will facilitate the development of strategies to maintain a healthy vaginal microbiome and prevent colonization with pathogenic bacteria such as E. coli that increase the risk for urinary tract infections, preterm labor and perinatal infection.
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Affiliation(s)
- Sabah Kalyoussef
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Edward Nieves
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Ellen Dinerman
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Colleen Carpenter
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Viswanathan Shankar
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Jamie Oh
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Berta Burd
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Ruth H. Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | | | - David N. Fredricks
- Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Rebecca P. Madan
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Marla J. Keller
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Betsy C. Herold
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, United States of America
- Department of Microbiology-Immunology, Albert Einstein College of Medicine, Bronx, New York, United States of America
- * E-mail:
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7
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Wang S, Lim J, Thomas K, Yan F, Angeletti RH, Schramm VL. A complex of methylthioadenosine/S-adenosylhomocysteine nucleosidase, transition state analogue, and nucleophilic water identified by mass spectrometry. J Am Chem Soc 2012; 134:1468-70. [PMID: 22239413 DOI: 10.1021/ja211176q] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An enzyme-stabilized nucleophilic water molecule has been implicated at the transition state of Escherichia coli methylthioadenosine nucleosidase (EcMTAN) by transition state analysis and crystallography. We analyzed the EcMTAN mass in complex with a femtomolar transition state analogue to determine whether the inhibitor and nucleophilic water could be detected in the gas phase. EcMTAN-inhibitor and EcMTAN-inhibitor-nucleophilic water complexes were identified by high-resolution mass spectrometry under nondenaturing conditions. The enzyme-inhibitor-water complex is sufficiently stable to exist in the gas phase.
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Affiliation(s)
- Shanzhi Wang
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA
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8
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Berezniuk I, Vu HT, Lyons PJ, Sironi JJ, Xiao H, Burd B, Setou M, Angeletti RH, Ikegami K, Fricker LD. Cytosolic carboxypeptidase 1 is involved in processing α- and β-tubulin. J Biol Chem 2011; 287:6503-17. [PMID: 22170066 DOI: 10.1074/jbc.m111.309138] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Purkinje cell degeneration (pcd) mouse has a disruption in the gene encoding cytosolic carboxypeptidase 1 (CCP1). This study tested two proposed functions of CCP1: degradation of intracellular peptides and processing of tubulin. Overexpression (2-3-fold) or knockdown (80-90%) of CCP1 in human embryonic kidney 293T cells (HEK293T) did not affect the levels of most intracellular peptides but altered the levels of α-tubulin lacking two C-terminal amino acids (delta2-tubulin) ≥ 5-fold, suggesting that tubulin processing is the primary function of CCP1, not peptide degradation. Purified CCP1 produced delta2-tubulin from purified porcine brain α-tubulin or polymerized HEK293T microtubules. In addition, CCP1 removed Glu residues from the polyglutamyl side chains of porcine brain α- and β-tubulin and also generated a form of α-tubulin with two C-terminal Glu residues removed (delta3-tubulin). Consistent with this, pcd mouse brain showed hyperglutamylation of both α- and β-tubulin. The hyperglutamylation of α- and β-tubulin and subsequent death of Purkinje cells in pcd mice was counteracted by the knock-out of the gene encoding tubulin tyrosine ligase-like-1, indicating that this enzyme hyperglutamylates α- and β-tubulin. Taken together, these results demonstrate a role for CCP1 in the processing of Glu residues from β- as well as α-tubulin in vitro and in vivo.
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Affiliation(s)
- Iryna Berezniuk
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Albrethsen J, Miller LM, Novikoff PM, Angeletti RH. Gel-based proteomics of liver cancer progression in rat. Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics 2011; 1814:1367-76. [DOI: 10.1016/j.bbapap.2011.05.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/26/2011] [Accepted: 05/26/2011] [Indexed: 02/08/2023]
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Yan F, Che FY, Nieves E, Weiss LM, Angeletti RH, Fiser A. Photo-assisted peptide enrichment in protein complex cross-linking analysis of a model homodimeric protein using mass spectrometry. Proteomics 2011; 11:4109-15. [PMID: 21834138 PMCID: PMC3465073 DOI: 10.1002/pmic.201100015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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: 01/11/2011] [Revised: 07/16/2011] [Accepted: 07/29/2011] [Indexed: 11/11/2022]
Abstract
MS analysis of cross-linked peptides can be used to probe protein contact sites in macromolecular complexes. We have developed a photo-cleavable cross-linker that enhances peptide enrichment, improving the signal-to-noise ratio of the cross-linked peptides in mass spectrometry analysis. This cross-linker utilizes nitro-benzyl alcohol group that can be cleaved by UV irradiation and is stable during the multiple washing steps used for peptide enrichment. The enrichment method utilizes a cross-linker that aids in eliminating contamination resulting from protein-based retrieval systems, and thus, facilitates the identification of cross-linked peptides. Homodimeric pilM protein from Pseudomonas aeruginosa 2192 (pilM) was investigated to test the specificity and experimental conditions. As predicted, the known pair of lysine side chains within 14 Å was cross-linked. An unexpected cross-link involving the protein's amino terminus was also detected. This is consistent with the predicted mobility of the amino terminus that may bring the amino groups within 19 Å of one another in solution. These technical improvements allow this method to be used for investigating protein-protein interactions in complex biological samples.
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Affiliation(s)
- Funing Yan
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Lim J, Menon V, Bitzer M, Miller LM, Madrid-Aliste C, Weiss LM, Fiser A, Angeletti RH. Frozen tissue can provide reproducible proteomic results of subcellular fractionation. Anal Biochem 2011; 418:78-84. [PMID: 21802400 DOI: 10.1016/j.ab.2011.06.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 06/29/2011] [Accepted: 06/30/2011] [Indexed: 10/18/2022]
Abstract
Differential detergent fractionation (DDF) is frequently used to partition fresh cells and tissues into distinct compartments. We have tested whether DDF can reproducibly extract and fractionate cellular protein components from frozen tissues. Frozen kidneys were sequentially extracted with three different buffer systems. Analysis of the three fractions with liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified 1693 proteins, some of which were common to all fractions and others of which were unique to specific fractions. Normalized spectral index (SI(N)) values obtained from these data were compared to evaluate both the reproducibility of the method and the efficiency of enrichment. SI(N) values between replicate fractions demonstrated a high correlation, confirming the reproducibility of the method. Correlation coefficients across the three fractions were significantly lower than those for the replicates, supporting the capability of DDF to differentially fractionate proteins into separate compartments. Subcellular annotation of the proteins identified in each fraction demonstrated a significant enrichment of cytoplasmic, cell membrane, and nuclear proteins in the three respective buffer system fractions. We conclude that DDF can be applied to frozen tissue to generate reproducible proteome coverage discriminating subcellular compartments. This demonstrates the feasibility of analyzing cellular compartment-specific proteins in archived tissue samples with the simple DDF method.
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Affiliation(s)
- Jihyeon Lim
- Laboratory for Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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12
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Basu J, Romney SL, Angeletti RH, Vermund SH, Nieves E, Kadish AS, Mikhail MS, Orr GA. Human immunodeficiency virus (HIV) antigens and RNA in HIV-seronegative women with cervical intraepithelial neoplasia. AIDS Res Hum Retroviruses 2009; 25:249-59. [PMID: 19292595 DOI: 10.1089/aid.2008.0096] [Citation(s) in RCA: 2] [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] [Indexed: 11/13/2022] Open
Abstract
While investigating whether proteins retrieved by cervicovaginal lavages (CVL) from women with cervical intraepithelial neoplasia (CIN) might correlate with risk of progression to invasive cervical cancer, we unexpectedly identified HIV gag and env glycoprotein in CVL from women with HIV-negative serology. HIV antigens were consistently identified by mass spectrometry (MS) in CVL from 4 women but were absent in CVL from the remaining 16 women. HIV serologies of all 20 patients were negative for both HIV-1 and HIV-2 antibodies. To validate the unexpected MS findings we performed Western blot (WB) and immunoaffinity chromatography (IC) analysis of CVL for HIV proteins, viral load assays of paired CVL and blood samples, and immunohistochemical HIV p24 expression in cervical biopsy specimens. WB analysis of CVL for prostate-specific antigen (PSA) was performed to exclude semen contamination as the source of HIV proteins. WB and IC results demonstrated the presence of HIV-1 gp41 and p24 antigens in four CVL that were identified by MS to have the HIV proteins. Despite negative serology, HIV RNA in CVL and HIV p24 in cervix biopsies were detected in patients with HIV antigen-positive CVL. HIV p24-positive CVL were PSA negative. All 20 subjects remained HIV seronegative throughout the study. Women with HIV proteins and RNA were comparatively older. Our findings suggest that CVL HIV proteins in women with CIN could be markers for unrecognized HIV exposure or subclinical infection. Proteomic screening of cervical secretions may be useful in identifying seronegative women exposed to HIV and/or at risk for AIDS.
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Affiliation(s)
- Jayasri Basu
- Department of Obstetrics and Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Seymour L. Romney
- Department of Obstetrics and Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Ruth H. Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Sten H. Vermund
- Institute of Global Health and Department of Pediatrics, Vanderbilt University, School of Medicine, Nashville, Tennessee 37232-0242
| | - Edward Nieves
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Anna S. Kadish
- Department of Obstetrics and Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York 10461
- Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Magdy S. Mikhail
- Department of Obstetrics and Gynecology and Women's Health, Albert Einstein College of Medicine, Bronx, New York 10461
| | - George A. Orr
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
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Verdier-Pinard P, Pasquier E, Xiao H, Burd B, Villard C, Lafitte D, Miller LM, Angeletti RH, Horwitz SB, Braguer D. Tubulin proteomics: towards breaking the code. Anal Biochem 2008; 384:197-206. [PMID: 18840397 DOI: 10.1016/j.ab.2008.09.020] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2008] [Revised: 09/12/2008] [Accepted: 09/15/2008] [Indexed: 01/02/2023]
Affiliation(s)
- Pascal Verdier-Pinard
- INSERM UMR 911 CRO2, Aix-Marseille Université, Faculté de Pharmacie, 27 bd Jean Moulin, 13285 Marseille cedex 05, France.
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Abstract
Isoniazid (INH) is an essential drug used to treat tuberculosis. The mycobactericidal agents are INH adducts [INH-NAD(P)] of the pyridine nucleotide coenzymes, which are generated in vivo after INH activation and which bind to, and inhibit, essential enzymes. The NADH-dependent enoyl-ACP reductase (InhA) and the NADPH-dependent dihydrofolate reductase (DfrA) have both been shown to be inhibited by INH-NAD(P) adducts with nanomolar affinity. In this paper, we profiled the Mycobacterium tuberculosis proteome using both the INH-NAD and INH-NADP adducts coupled to solid supports and identified, in addition to InhA and DfrA, 16 other proteins that bind these adducts with high affinity. The majority of these are predicted to be pyridine nucleotide-dependent dehydrogenases/reductases. They are involved in many cellular processes, including S-adenosylmethionine-dependent methyl transfer reactions, pyrimidine and valine catabolism, the arginine degradative pathway, proton and potassium transport, stress response, lipid metabolism, and riboflavin biosynthesis. The targeting of multiple enzymes could, thus, account for the pleiotropic effects of, and powerful mycobactericidal properties of, INH.
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Affiliation(s)
- Argyrides Argyrou
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Lianji Jin
- Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Linda Siconilfi-Baez
- Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Ruth H. Angeletti
- Laboratory for Macromolecular Analysis & Proteomics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - John S. Blanchard
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
- To whom correspondence should be addressed: John S. Blanchard Department of Biochemistry Albert Einstein College of Medicine 1300 Morris Park Avenue Bronx, NY 10461 USA Tel: (718) 430-3096; Fax: (718) 430-8565; E-mail:
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15
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Basu J, Duttagupta C, Angeletti RH, Nieves E, Vermund SH, Romney SL. HIV-associated cellular proteins in human cervicovaginal lavage samples from HIV-negative women. Retrovirology 2006. [PMCID: PMC1716893 DOI: 10.1186/1742-4690-3-s1-p7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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16
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Xiao Y, Nieves E, Angeletti RH, Orr GA, Wolkoff AW. Rat organic anion transporting protein 1A1 (Oatp1a1): purification and phosphopeptide assignment. Biochemistry 2006; 45:3357-69. [PMID: 16519530 PMCID: PMC2505048 DOI: 10.1021/bi052437v] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [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: 01/08/2023]
Abstract
Rat organic anion transporting protein 1a1 (oatp1a1), a hepatocyte basolateral plasma membrane protein, mediates transport of various amphipathic compounds. Our previous studies indicated that serine phosphorylation of a single tryptic peptide inhibits its transport activity without changing its cell surface content. The site of phosphorylation is unknown and was the subject of the present study. Following immunoaffinity chromatographic purification from rat liver, oatp1a1 was subjected to trypsin digestion and MALDI-TOF. Except for predicted N-glycosylated peptides, 97% of oatp1a1 tryptic peptides were observed. A single tryptic phosphopeptide was found in the C-terminus (aa 626-647), existing in unphosphorylated or singly or doubly phosphorylated forms and sensitive to alkaline phosphatase treatment. The beta-elimination reaction resulted in a mass loss of 98 or 196 Da from this peptide, and subsequent Michael addition with cysteamine increased masses by the predicated 77 and 154 Da, indicating that oatp1a1 can be singly or doubly phosphorylated at serine or threonine residues in the C-terminal sequence SSATDHT (aa 634-640). Subsequent tandem MS/MS analysis revealed that phosphorylation at S634 accounted for all singly phosphorylated peptide, while phosphorylation at S634 and S635 accounted for all doubly phosphorylated peptide. These findings identify the site of oatp1a1 phosphorylation and demonstrate that it is an ordered process, in which phosphorylation at S634 precedes that at S635. The mechanism by which phosphorylation results in loss of transport activity in hepatocytes remains to be established. Whether phosphorylation near the C-terminus inhibits C-terminal oligomerization of oatp1a1, required for normal transport function, can be speculated upon but is as yet unknown.
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Affiliation(s)
- Yansen Xiao
- Marion Bessin Liver Research Center, Department of Developmental and Molecular Biology, Laboratory for Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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17
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Basu J, Romney SL, Angeletti RH, Nieves E, Xiao H, Orr GA. Proteomic Analysis of Cervicovaginal Lavage Samples (CVL): Identification of Human Immunodeficiency Virus (HIV) Proteins. Retrovirology 2005. [DOI: 10.1186/1742-4690-2-s1-p150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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18
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Pedrioli PGA, Eng JK, Hubley R, Vogelzang M, Deutsch EW, Raught B, Pratt B, Nilsson E, Angeletti RH, Apweiler R, Cheung K, Costello CE, Hermjakob H, Huang S, Julian RK, Kapp E, McComb ME, Oliver SG, Omenn G, Paton NW, Simpson R, Smith R, Taylor CF, Zhu W, Aebersold R. A common open representation of mass spectrometry data and its application to proteomics research. Nat Biotechnol 2005; 22:1459-66. [PMID: 15529173 DOI: 10.1038/nbt1031] [Citation(s) in RCA: 630] [Impact Index Per Article: 33.2] [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]
Abstract
A broad range of mass spectrometers are used in mass spectrometry (MS)-based proteomics research. Each type of instrument possesses a unique design, data system and performance specifications, resulting in strengths and weaknesses for different types of experiments. Unfortunately, the native binary data formats produced by each type of mass spectrometer also differ and are usually proprietary. The diverse, nontransparent nature of the data structure complicates the integration of new instruments into preexisting infrastructure, impedes the analysis, exchange, comparison and publication of results from different experiments and laboratories, and prevents the bioinformatics community from accessing data sets required for software development. Here, we introduce the 'mzXML' format, an open, generic XML (extensible markup language) representation of MS data. We have also developed an accompanying suite of supporting programs. We expect that this format will facilitate data management, interpretation and dissemination in proteomics research.
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Affiliation(s)
- Patrick G A Pedrioli
- Institute for Systems Biology, 1441 North 34 Street, Seattle, Washington 98103-8904, USA
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19
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Wang F, Shi W, Nieves E, Angeletti RH, Schramm VL, Grubmeyer C. A transition-state analogue reduces protein dynamics in hypoxanthine-guanine phosphoribosyltransferase. Biochemistry 2001; 40:8043-54. [PMID: 11434773 DOI: 10.1021/bi010203f] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [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: 11/30/2022]
Abstract
Hypoxanthine-guanine phosphoribosyltransferase (HGPRT) is the key enzyme in purine base salvage in humans and in purine auxotrophs, including Plasmodium falciparum, the leading cause of malaria. Hydrogen/deuterium (H/D) exchange into amide bonds, quantitated by on-line HPLC and mass spectrometry, has been used to compare the dynamic and conformational properties of human HGPRT alone, the HGPRT-GMP-Mg(2+) complex, the HGPRT-IMP-MgPPi <==> HGPRT-Hx-MgPRPP equilibrating mixture, and the transition-state analogue complex HGPRT-ImmGP-MgPPi. The rate and extent of H/D exchange of 26 peptic peptides, spanning 91% of the primary structure, have been monitored. Human HGPRT has 207 amide H/D exchange sites. After 1 h in D2O, HGPRT alone exchanges 160, HGPRT-GMP-Mg(2+) exchanges 154, the equilibrium complex exchanges 139, and the transition-state analogue complex exchanges 126 of these amide protons. H/D exchange rates are correlated with structure for peptides in (1) catalytic site loops, (2) a connected peptide of the subunit interface of the tetramer, and (3) a loop buried in the catalytic site. Structural properties related to H/D exchange are defined from crystallographic studies of the HGPRT-GMP-Mg(2+) and HGPRT-ImmGP-MgPPi complexes. Transition-state analogue binding strengthens the interaction between subunits and tightens the catalytic site loops. The solvent exchange dynamics in specific peptides correlates with hydrogen bond patterns, solvent access, crystallographic B-factors, and ligand exchange rates. Solvent exchange reveals loop dynamics in the free enzyme, Michaelis complexes, and the complex with the bound transition-state analogue. Proton transfer paths, rather than dynamic motion, are required to explain exchange into a buried catalytic site peptide in the complex with the bound transition-state analogue.
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Affiliation(s)
- F Wang
- Laboratory for Macromolecular Analysis and Proteomics, Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, USA
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20
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Christensen ST, Guerra C, Wada Y, Valentin T, Angeletti RH, Satir P, Hamasaki T. A regulatory light chain of ciliary outer arm dynein in Tetrahymena thermophila. J Biol Chem 2001; 276:20048-54. [PMID: 11274140 DOI: 10.1074/jbc.m008412200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [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
Ciliary beat frequency is primarily regulated by outer arm dyneins (22 S dynein). Chilcote and Johnson (Chilcote, T. J., and Johnson, K. A. (1990) J. Biol. Chem. 256, 17257-17266) previously studied isolated Tetrahymena 22 S dynein, identifying a protein p34, which showed cAMP-dependent phosphorylation. Here, we characterize the molecular biochemistry of p34 further, demonstrating that it is the functional ortholog of the 22 S dynein regulatory light chain, p29, in Paramecium. p34, thiophosphorylated in isolated axonemes in the presence of cAMP, co-purified with 22 S dynein and not with inner arm dynein (14 S dynein). Isolated 22 S dynein containing phosphorylated p34 showed approximately 70% increase in in vitro microtubule translocation velocity compared with its unphosphorylated counterpart. Extracted p34 rebound to isolated 22 S dynein from either Tetrahymena or Paramecium but not to 14 S dynein from either ciliate. Binding of radiolabeled p34 to 22 S dynein was competitive with p29. Phosphorylated p34 was not present in axonemes isolated from a mutant lacking outer arms. Two-dimensional gel electrophoresis followed by phosphorimaging revealed at least five phosphorylated p34-related spots, consistent with multiple phosphorylation sites in p34 or perhaps multiple isoforms of p34. These new features suggest that a class of outer arm dynein light chains including p34 regulates microtubule sliding velocity and consequently ciliary beat frequency through phosphorylation.
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Affiliation(s)
- S T Christensen
- Departments of Anatomy and Structural Biology and Developmental and Molecular Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA
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21
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Wang C, Fu M, Angeletti RH, Siconolfi-Baez L, Reutens AT, Albanese C, Lisanti MP, Katzenellenbogen BS, Kato S, Hopp T, Fuqua SA, Lopez GN, Kushner PJ, Pestell RG. Direct acetylation of the estrogen receptor alpha hinge region by p300 regulates transactivation and hormone sensitivity. J Biol Chem 2001; 276:18375-83. [PMID: 11279135 DOI: 10.1074/jbc.m100800200] [Citation(s) in RCA: 257] [Impact Index Per Article: 11.2] [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: 11/06/2022] Open
Abstract
Regulation of nuclear receptor gene expression involves dynamic and coordinated interactions with histone acetyl transferase (HAT) and deacetylase complexes. The estrogen receptor (ERalpha) contains two transactivation domains regulating ligand-independent and -dependent gene transcription (AF-1 and AF-2 (activation functions 1 and 2)). ERalpha-regulated gene expression involves interactions with cointegrators (e.g. p300/CBP, P/CAF) that have the capacity to modify core histone acetyl groups. Here we show that the ERalpha is acetylated in vivo. p300, but not P/CAF, selectively and directly acetylated the ERalpha at lysine residues within the ERalpha hinge/ligand binding domain. Substitution of these residues with charged or polar residues dramatically enhanced ERalpha hormone sensitivity without affecting induction by MAPK signaling, suggesting that direct ERalpha acetylation normally suppresses ligand sensitivity. These ERalpha lysine residues also regulated transcriptional activation by histone deacetylase inhibitors and p300. The conservation of the ERalpha acetylation motif in a phylogenetic subset of nuclear receptors suggests that direct acetylation of nuclear receptors may contribute to additional signaling pathways involved in metabolism and development.
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Affiliation(s)
- C Wang
- Department of Developmental and Molecular Biology, Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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22
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Affiliation(s)
- R H Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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23
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Holtzer ME, Bretthorst GL, d'Avignon DA, Angeletti RH, Mints L, Holtzer A. Temperature dependence of the folding and unfolding kinetics of the GCN4 leucine zipper via 13C(alpha)-NMR. Biophys J 2001; 80:939-51. [PMID: 11159461 PMCID: PMC1301292 DOI: 10.1016/s0006-3495(01)76073-0] [Citation(s) in RCA: 25] [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] [Indexed: 10/21/2022] Open
Abstract
Studies by one-dimensional NMR are reported on the interconversion of folded and unfolded forms of the GCN4 leucine zipper in neutral saline buffer. The peptide bears 99% 13C(alpha) labels at three sites: V9, L12, and G31. Time-domain 13C(alpha)-NMR spectra are interpreted by global Bayesian lineshape analysis to extract the rate constants for both unfolding and folding as functions of temperature in the range 47-71 degrees C. The data are well fit by the assumption that the same rate constants apply at each labeled site, confirming that only two conformational states need be considered. Results show that 1) both processes require a free energy of activation; 2) unfolding is kinetically enthalpy-opposed and entropy-driven, while folding is the opposite; and 3) the transition state dimer ensemble averages approximately 40% helical. The activation parameters for unfolding, derived from NMR data at the elevated temperatures where both conformations are populated, lead to estimates of the rate constant at low temperatures (5-15 degrees C) that agree with extant values determined by stopped-flow CD via dilution from denaturing media. However, the corresponding estimated values for the folding rate constant are larger by two to three orders of magnitude than those obtained by stopped flow. We propose that this apparent disagreement is caused by the necessity, in the stopped-flow experiment, for initiation of new helices as the highly denaturant-unfolded molecule adjusts to the newly created benign solvent conditions. This must reduce the success rate of collisions in producing the folded molecule. In the NMR determinations, however, the unfolded chains always have a small, but essential, helix content that makes such initiation unnecessary. Support for this hypothesis is adduced from recent extant experiments on the helix-coil transition in single-chain helical peptides and from demonstration that the folding rate constants for coiled coils, as obtained by stopped flow, are influenced by the nature of the denaturant used.
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Affiliation(s)
- M E Holtzer
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, USA
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24
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25
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Abstract
Homo- and heterodimeric hemoglobins have been isolated from the red cells of the arcid clam Noetia ponderosa (Np). These hemoglobins bind oxygen cooperatively. An extensively studied dimeric hemoglobin from another arcid clam, Scapaharca inaequivalvis, exhibits a molecular mechanism for cooperative ligand binding that is radically different from tetrameric vertebrate hemoglobins. In this study, the two chains found in both Noetia hemoglobins are sequenced and compared to the hemoglobins of the related clam S. inaequivalvis to determine whether Noetia hemoglobins have the structural basis for the same unusual mechanism for cooperative ligand binding and to inquire about the structural basis of absence of tetramers. Although the Noetia sequences are homologous to the Scapharca sequences, critical differences exist. The lack of tetramerization of Np subunits is most likely related to the absence of critical residues in the A and G helices that stabilize the interdimer contact seen in the Scapharca Hb tetramer. The lower affinity of the homodimer (Np-I), but particularly the heterodimer (Np-II) with respect to the homodimer and heterotetramer of Scapharca, can be due to (i) changes in the proximal heme environment and (ii) changes in the dimer interface. Interactions between Asn 100 and the heme of the other subunit are altered in Np-II due to the substitution of this residue by methionine, possibly causing the reduced O(2) affinity of the heterodimer of Noetia. (iii) Sequence changes in the E and F helices present in Np-I and Np-II could also contribute to the effect through interfacial changes. In particular, the substitution of Val for Thr in position 72 is expected to have a substantial influence on the interface. We conclude that Np dimers have the structural basis for a direct heme-heme interaction mechanism for cooperativity, as in Scapharca, but there are enough sequence changes to suggest that the pathway of interaction might be somewhat different.
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Affiliation(s)
- R L Nagel
- Division of Hematology, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York 10461, USA.
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26
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Wang F, Miles RW, Kicska G, Nieves E, Schramm VL, Angeletti RH. Immucillin-H binding to purine nucleoside phosphorylase reduces dynamic solvent exchange. Protein Sci 2000; 9:1660-8. [PMID: 11045613 PMCID: PMC2144693 DOI: 10.1110/ps.9.9.1660] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [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: 10/21/2022]
Abstract
The rate and extent of hydrogen/deuterium (H/D) exchange into purine nucleoside phosphorylase (PNP) was monitored by electrospray ionization mass spectrometry (ESI-MS) to probe protein conformational and dynamic changes induced by a substrate analogue, products, and a transition state analogue. The genetic deficiency of PNP in humans is associated with severe T-cell immunodeficiency, while B-cell immunity remains functional. Inhibitors of PNP have been proposed for treatment of T-cell leukemia, to suppress the graft-vs.-host response, or to counter type IV autoimmune diseases without destroying humoral immunity. Calf spleen PNP is a homotrimer of polypeptide chains with 284 amino residues, molecular weight 31,541. Immucillin-H inhibits PNP with a Kd of 23 pM when only one of the three catalytic sites is occupied. Deuterium exchange occurs at 167 slow-exchange sites in 2 h when no catalytic site ligands are present. The substrate analogue and product prevented H/D exchange at 10 of the sites. Immucillin-H protected 32 protons from exchange at full saturation. When one of the three subunits of the homotrimer is filled with immucillin-H, and 27 protons are protected from exchange in all three subunits. Deuterium incorporation in peptides from residues 132-152 decreased in all complexes of PNP. The rate and/or extent of deuterium incorporation in peptides from residues 29-49, 50-70, 81-98, and 112-124 decreased only in the complex with the transition state analogue. The peptide-specific H/D exchange demonstrates that (1) the enzyme is most compact in the complex with immucillin-H, and (2) filling a single catalytic site of the trimer reduces H/D exchange in the same peptides in adjacent subunits. The peptides most highly influenced by the inhibitor surround the catalytic site, providing evidence for reduced protein dynamic motion caused by the transition state analogue.
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Affiliation(s)
- F Wang
- Laboratory for Macromolecular Analysis and Proteomics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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27
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Sauve AA, Deng H, Angeletti RH, Schramm VL. A Covalent Intermediate in CD38 Is Responsible for ADP-Ribosylation and Cyclization Reactions. J Am Chem Soc 2000. [DOI: 10.1021/ja001139c] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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Fu M, Wang C, Reutens AT, Wang J, Angeletti RH, Siconolfi-Baez L, Ogryzko V, Avantaggiati ML, Pestell RG. p300 and p300/cAMP-response element-binding protein-associated factor acetylate the androgen receptor at sites governing hormone-dependent transactivation. J Biol Chem 2000; 275:20853-60. [PMID: 10779504 DOI: 10.1074/jbc.m000660200] [Citation(s) in RCA: 282] [Impact Index Per Article: 11.8] [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
The androgen receptor (AR) is a sequence-specific DNA-binding protein that plays a key role in prostate cancer cellular proliferation by dihydrotestosterone and the induction of secondary sexual characteristics. In this study we demonstrate that the AR can be modified by acetylation in vitro and in vivo. p300 and p300/cAMP-response element-binding protein acetylated the AR at a highly conserved lysine-rich motif carboxyl-terminal to the zinc finger DNA-binding domain. [(14)C]acetate-labeling experiments demonstrated that AR acetylation by p300 in cultured cells requires the same residues identified in vitro. Point mutation of the AR acetylation site (K632A/K633A) abrogated dihydrotestosterone-dependent transactivation of the AR in cultured cells. Mutation of the p300 CH3 region or the p300/cAMP-response element-binding protein histone acetylase domain reduced ligand-dependent AR function. The identification of the AR as a direct target of histone acetyltransferase co-activators has important implications for targeting inhibitors of AR function.
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Affiliation(s)
- M Fu
- Albert Einstein Cancer Center, Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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29
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Stridsberg M, Angeletti RH, Helle KB. Characterisation of N-terminal chromogranin A and chromogranin B in mammals by region-specific radioimmunoassays and chromatographic separation methods. J Endocrinol 2000; 165:703-14. [PMID: 10828855 DOI: 10.1677/joe.0.1650703] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Chromogranin A (CgA) and chromogranin B (CgB) are acidic proteins stored in and released from hormone granules in endocrine and neuroendocrine tissue. The chromogranins are postulated to serve as pro-hormones to generate biologically active peptides, which may influence hormonal release and vascular functions or have antibacterial functions. Although N-terminal and C-terminal regions show some species amino acid homology, the chromogranins as a whole display considerable interspecies differences, which prevents their use in comparative studies of biological functions. We present four new radioimmunoassays for the measurement of defined N-terminal regions of CgA and CgB. A new radioimmunoassay for measurement of intact bovine CgA has also been developed. With these assays and two previously published ones, we have compared the cross-reactivity of chromogranins from man, cattle, sheep, goat, pig and horse and compared adrenomedullar content and serum levels of CgA from these species. We have also studied the influence of peptide concentrations and the ionic strength of the mobile phase on molecular weight estimations. Assays with antibodies directed against the N-terminal parts of CgA and CgB showed sufficient interspecies cross-reactivity to allow comparative quantification of the circulating levels in man, cattle, sheep, goat, pig and horse. Assays measuring the intact human or bovine CgA were not suitable for comparative purposes in samples from sheep, goat, pig and horse. Molecular interactions between vasostatin immunoreactive material and intact bovine CgA were demonstrated in gel permeation studies, suggesting that conclusions about the degree of N-terminal processing from elution profiles should be made with caution. Reliable interspecies comparison of chromogranins is difficult, but measurements with region-specific assays may be helpful to study concentrations of chromogranins and chromogranin-related peptides.
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Affiliation(s)
- M Stridsberg
- Department of Medical Sciences, Clinical Chemistry, University Hospital, S-751 85 Uppsala, Sweden.
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30
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Holtzer ME, Braswell E, Angeletti RH, Mints L, Zhu D, Holtzer A. Ultracentrifuge and circular dichroism studies of folding equilibria in a retro GCN4-like leucine zipper. Biophys J 2000; 78:2037-48. [PMID: 10733982 PMCID: PMC1300796 DOI: 10.1016/s0006-3495(00)76751-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [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: 11/16/2022] Open
Abstract
Equilibrium ultracentrifuge and circular dichroism (CD) studies of a retropeptide of a GCN4-like leucine zipper in neutral saline buffer are reported as functions of temperature. Ultracentrifuge results indicate the presence of three oligomeric species: monomer, dimer, and tetramer, in quantifiable amounts, and the data provide values for the standard DeltaG, DeltaH, and DeltaS for interconversion. CD at 222 nm displays the strong concentration dependence characteristic of dissociative unfolding, but also shows a helicity far below that of the parent propeptide. Remarkably enough, the CD at 222 nm shows an extremum in the region between 0 and 20 degrees C. At higher T, the usual cooperative unfolding is observed. Comparable data are presented for a mutant retropeptide, in which a single asparagine residue is restored to the characteristic heptad position it occupies in the propeptide. The mutant shows marked differences from its unmutated relative in both thermodynamic properties and CD, although the oligomeric ensemble also comprises monomers, dimers, and tetramers. The mutant is closer in helicity to the parent propeptide but is less stable. These findings do not support either of the extant views on retropeptides. The behavior seen is consistent neither with the view that retropeptides should have the same structure as propeptides nor with the view that they should have the same structure but opposite chirality. The simultaneous availability of oligomeric population data and CD allows the latter to be dissected into individual contributions from monomers, dimers, and tetramers. This dissection yields explanations for the observed extrema in curves of CD (222 nm) versus T and reveals that the dimer population in both retropeptides undergoes "cold denaturation."
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Affiliation(s)
- M E Holtzer
- Department of Chemistry, Washington University, St. Louis, Missouri 63130-4899, USA
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31
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Russell J, Zhao W, Christ G, Ashok S, Angeletti RH. Ca2+-induced increases in steady-state concentrations of intracellular calcium are not required for inhibition of parathyroid hormone secretion. Mol Cell Biol Res Commun 1999; 1:221-6. [PMID: 10425230 DOI: 10.1006/mcbr.1999.0135] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been well established that increases in extracellular calcium concentration ([Ca2+]) inhibit parathyroid hormone (PTH) secretion. The effects of [Ca2+] are mediated through a G-protein-coupled receptor that has been cloned and characterized. Additionally, it has been demonstrated in parathyroid cells that an increase in [Ca2+] results in an increase in steady-state levels of intracellular calcium ([Ca2+]i). At present, it has not been fully resolved whether changes in [Ca2+]i are related to changes in PTH secretion. In the current study, the effect of increased [Ca2+] on PTH secretion and the connection regarding changes in concentrations of intracellular calcium [Ca2+]i have been examined in primary cultures of bovine parathyroid cells. PTH secretion was measured by radioimmunoassay and intracellular calcium was determined by single cell calcium imaging. Bovine parathyroid cells pre-incubated with either 0.5 or 1 mM calcium responded to rapid increases in [Ca2+] (> or = 0.5 mM) with an immediate and sustained increase in steady-state levels of [Ca2+]i that persisted for time intervals greater than 15 minutes. Although the magnitude of the sustained increase in [Ca2+]i varied among individual cells (approximately 40% to > 300%), the overall pattern and course of time were similar in all cells examined (n = 142). In all trials, [Ca2+]i immediately returned to baseline levels following the addition of the calcium chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). Additional control studies, however, suggest that sustained increases in [Ca2+]i do not correlate with regulation of parathyroid hormone secretion. Sustained elevations of [Ca2+]i were not observed when [Ca2+] was gradually increased by the addition of 0.1 mM increments at 1 minute intervals. Furthermore, the effect on inhibition of PTH secretion was the same regardless of whether [Ca2+] was increased by gradual or rapid addition.
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Affiliation(s)
- J Russell
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Affiliation(s)
- R H Angeletti
- Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Angeletti RH. Design of useful peptide antigens. J Biomol Tech 1999; 10:2-10. [PMID: 19499000 PMCID: PMC2291584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Well-designed anti-peptide antibodies provide the specificity and control for everyday and cutting-edge applications. Pragmatic peptide antigen design principles can be used to help ensure production of successful antibodies. Issues of peptide chemistry, sequence selection, antigen preparation, antibody handling, and experimental needs must be taken into consideration in the planning stages.
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Affiliation(s)
- R H Angeletti
- Laboratory for Macromolecular Analysis, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Angeletti RH, Bergwerk AJ, Novikoff PM, Wolkoff AW. Dichotomous development of the organic anion transport protein in liver and choroid plexus. Am J Physiol 1998; 275:C882-7. [PMID: 9730973 DOI: 10.1152/ajpcell.1998.275.3.c882] [Citation(s) in RCA: 32] [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] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Both adult liver and choroid plexus express the organic anion transport protein (oatp1) and transport [35S]bromosulfophthalein (BSP). Studies of the developing rat liver reveal that oatp1 mRNA and protein do not begin to be expressed until 15 days postnatal and are at adult levels by 30 days. Uptake of [35S]BSP follows the same time course. In contrast, neonatal rat choroid plexus expresses oatp1 mRNA and protein. When quantified on a weight basis, the uptake of [35S]BSP in choroid plexus is lower in the adult than at earlier stages of development. Although fluorescence confocal microscopy of adult rat choroid plexus shows that oatp is localized to the apical surface, facing the cerebrospinal fluid, this method reveals an intracellular localization of oatp1 in the neonate. Approximately 12 wk are required for the appearance of the adult pattern of distribution. Changes in the localization and activity of oatp1 during development could play an important role in the pathobiology of maturation of the liver and the central nervous system.
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Affiliation(s)
- R H Angeletti
- Department of Developmental Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Abstract
Interleukin-8 (IL-8) is a chemokine important in inflammatory processes. Homology cloning experiments performed using bovine parathyroid cDNA and degenerate primers encoding transmembrane regions III and VI of peptide and protein hormone G-protein coupled receptors identified a set of known receptors not previously identified in the parathyroid. Among these was the IL-8 type B receptor. Incubation of freshly isolated bovine parathyroid cells with recombinant IL-8 for 6-48 h produced an increase in the levels of mRNA for parathyroid hormone (PTH). The levels of PTH secreted in response to nanomolar amounts of IL-8 were also elevated in cells incubated for 1 h with IL-8. Differential display analysis of mRNA from parathyroid cells, incubated in the presence and absence of IL-8, permitted the identification of cDNA clones for RNA species whose expression was either elevated or suppressed. These experiments suggest that IL-8 and inflammatory events play a role in bone homeostasis through actions on the parathyroid gland.
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Affiliation(s)
- R H Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Wang F, Scapin G, Blanchard JS, Angeletti RH. Substrate binding and conformational changes of Clostridium glutamicum diaminopimelate dehydrogenase revealed by hydrogen/deuterium exchange and electrospray mass spectrometry. Protein Sci 1998; 7:293-9. [PMID: 9521104 PMCID: PMC2143904 DOI: 10.1002/pro.5560070208] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
C. glutamicum meso-diaminopimelate dehydrogenase is an enzyme of the L-lysine biosynthetic pathway in bacteria. The binding of NADPH and diaminopimelate to the recombinant, overexpressed enzyme has been analyzed using hydrogen/deuterium exchange and electrospray ionization/mass spectrometry. NADPH binding reduces the extent of deuterium exchange, as does the binding of diaminopimelate. Pepsin digestion of the deuterated enzyme and enzyme-substrate complexes coupled with liquid chromatography/mass spectrometry have allowed the identification of eight peptides whose deuterium exchange slows considerably upon the binding of the substrates. These peptides represent regions known or thought to bind NADPH and diaminopimelate. One of these peptides is located at the interdomain hinge region and is proposed to be exchangeable in the "open," catalytically inactive, conformation but nonexchangeable in the "closed," catalytically active conformation formed after NADPH and diaminopimelate binding and domain closure. Furthermore, the dimerization region has been localized by this method, and this study provides an example of detecting protein-protein interface regions using hydrogen/deuterium exchange and electrospray ionization.
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Affiliation(s)
- F Wang
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Hörig H, Papadopoulos NJ, Vegh Z, Palmieri E, Angeletti RH, Nathenson SG. An in vitro study of the dynamic features of the major histocompatibility complex class I complex relevant to its role as a versatile peptide-receptive molecule. Proc Natl Acad Sci U S A 1997; 94:13826-31. [PMID: 9391112 PMCID: PMC28392 DOI: 10.1073/pnas.94.25.13826] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [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: 02/05/2023] Open
Abstract
The major histocompatibility complex class I complex consists of a heavy chain and a light chain (beta2-microglobulin, beta2m), which assemble with a short endogenously derived peptide in the endoplasmic reticulum. The class I peptide can be directly exchanged, either at the cell surface or, as recently described, in vesicles of the endocytic compartments, thus allowing exogenous peptides to enter the class I presentation pathway. To probe the interactions between the components of the class I molecule, we analyzed the exchange of peptide and beta2m by using purified, recombinant H2-Kb/peptide complexes in a cell-free in vitro system. The exchange of competitor peptide was primarily dependent on the off-rate of the original peptide in the class I binding groove. Peptide exchange was not enhanced by the presence of exogenous beta2m, as exchange occurred to the same extent in its absence. Thus, the exchange of peptide and beta2m are independent events. The exchange rate of beta2m also was not affected by the dissociation rates of the original peptides. Furthermore, peptides could substantially exchange into class I molecules over a pH range of 5.5 to 7.5, conditions prevalent in certain endocytic compartments. We conclude that the dynamic properties of the components of class I molecules explain its function as a highly peptide-receptive molecule. The major histocompatibility complex class I can readily receive peptides independent of the presence of exogenous beta2m, even at a low pH. Such properties are relevant to class I peptide acquisition, which can occur at the cell surface, as well as in specialized endosomes.
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Affiliation(s)
- H Hörig
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Affiliation(s)
- R H Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Kadish AS, Ho GY, Burk RD, Wang Y, Romney SL, Ledwidge R, Angeletti RH. Lymphoproliferative responses to human papillomavirus (HPV) type 16 proteins E6 and E7: outcome of HPV infection and associated neoplasia. J Natl Cancer Inst 1997; 89:1285-93. [PMID: 9293919 DOI: 10.1093/jnci/89.17.1285] [Citation(s) in RCA: 123] [Impact Index Per Article: 4.6] [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: 02/05/2023] Open
Abstract
BACKGROUND Infection with human papillomavirus (HPV) type 16 (HPV16) is a major cause of high-grade cervical intraepithelial neoplasia (CIN). Experiments were planned to evaluate the role of cell-mediated immunity (e.g., lymphocyte proliferation) against HPV in the natural history of HPV-associated neoplasia and to identify antigenic sequences of the HPV16 proteins E6 and E7 against which an immune response may confer protection. METHODS Forty-nine women with abnormal cervical cytology and biopsy-confirmed CIN were followed through one or more clinic visits. Lymphoproliferative responses of peripheral blood mononuclear cells to HPV16 E6 and E7 peptides were assessed in long-term (3-week) cultures. HPV DNA was detected in cervicovaginal lavage by means of polymerase chain reaction and Southern blotting. Disease status was determined by cervical cytologic examination and colposcopy. Reported P values are two-sided. RESULTS Subjects with positive lymphoproliferative responses to E6 and/or E7 peptides were more likely to be HPV negative at the same clinic visit than were nonresponders (P = .039). Subjects who were negative for HPV and those with a low viral load were more likely to be responders than were those with a high viral load (P for trend = .037). Responses to N-terminal E6 peptide 369 were associated with absence of HPV infection at the same clinic visit (P = .015). Subjects with positive responses to E6 or E7 peptides at one clinic visit were 4.4 times more likely to be HPV negative at the next visit than were nonresponders (P = .142). Responses to E6 peptide 369 and/or E7 C-terminal peptide 109 were associated with an absence of HPV infection (P = .02 for both) and an absence of CIN (P = .04 and .02, respectively) at the next visit. CONCLUSIONS Lymphoproliferative responses to specific HPV16 E6 and E7 peptides appear to be associated with the clearance of HPV infection and the regression of CIN.
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Affiliation(s)
- A S Kadish
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Angeletti RH, Novikoff PM, Juvvadi SR, Fritschy JM, Meier PJ, Wolkoff AW. The choroid plexus epithelium is the site of the organic anion transport protein in the brain. Proc Natl Acad Sci U S A 1997; 94:283-6. [PMID: 8990200 PMCID: PMC19316 DOI: 10.1073/pnas.94.1.283] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.7] [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: 02/03/2023] Open
Abstract
The mRNA for organic anion transport protein (oatp) was previously shown to be present in abundance in liver and kidney, and in small amounts in brain. Data obtained from experiments with reverse transcriptase-PCR techniques and in situ hybridization analysis showed that the oatp mRNA is present within the brain, localized to the choroid plexus. A sequence-specific antibody to the oatp polypeptide demonstrated the presence of the expected polypeptide with a molecular weight of 80,000 plus an immunoreactive species with a higher molecular weight in preparations of choroid plexus membranes. Examination of the choroid plexus by fluorescence confocal microscopy revealed that immunoreactive oatp polypeptide is localized to the apical surface of the choroid plexus epithelial cells, which contacts the cerebrospinal fluid. This localization of oatp is consistent with previous experiments showing vectorial transport of organic anions between the choroid plexus and the cerebrospinal fluid.
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Affiliation(s)
- R H Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Abstract
Furin is a dibasic endopeptidase responsible for the proteolytic maturation of many precursor proteins in the secretory and endocytic pathways of mammalian cells. The levels of furin expression in most cells are very low, and this has hampered attempts to identify the intracellular compartments in which endogenous furin is localized. We have used a specific antibody reagent to a sequence in the carboxy terminus of furin to perform immunofluorescent staining of mammalian cell lines. This antibody was sensitive enough to detect staining for furin in various cell lines. For the most part, furin staining was confined to a juxtanuclear structure characteristic of the Golgi complex. Analyses by video microscopy and confocal microscopy showed that the distribution of furin was distinct from that of mannosidase II, a marker of the Golgi stack, and most closely resembled that of TGN38, a marker of the trans-Golgi network. Therefore, our results suggest that endogenous furin is predominantly localized to the area of the Golgi complex, most likely within the trans-Golgi network.
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Affiliation(s)
- J Shapiro
- Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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Aardal S, Aardal NP, Larsen TH, Angeletti RH, Stridsberg M, Taupenot L, Aunis D, Helle KB. Human pheochromocytoma: different patterns of catecholamines and chromogranins in the intact tumour, urine and serum in clinically unsuspected cases. Scand J Clin Lab Invest 1996; 56:511-23. [PMID: 8903113 DOI: 10.3109/00365519609088807] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [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: 02/02/2023]
Abstract
Clinically unsuspected pheochromocytoma is usually discovered either at autopsy or during surgical intervention for unrelated conditions, despite often enormous neoplastic masses producing and storing catecholamine (CA). In order to assess whether these tumours share some common features we have compiled data for six patients admitted to hospital without previous diagnosis of their pheochromocytoma. The clinical variables and the morphological and immunohistochemical characteristics of the tumours revealed that these cases represented quite different expressions of adrenomedullary neoplasms. They differed not only with respect to nuclear ploidity and overall cytoplasmic morphology but also in catecholamine storage and expression of immunoreactive chromogranin A sequences in the intact tissue. In two of the patients hypertension had been overlooked as a diagnostic indicator of their CA-producing tumours. There was no clear relationship between the mean arterial pressure, the tumour content of CA and the serum levels of CA. Processed chromogranin A dominated in the serum of the two hypertensive cases. The 24-h urine values of CA and its main metabolite (vanillin mandelic acid) were, together with the serum values of chromogranin A and B, proportional to tumour mass and provided the most reliable diagnostic indicators for the non-hypertensive as well as the hypertensive cases.
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Affiliation(s)
- S Aardal
- Department of Surgery, University Hospital, Bergen, Norway
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Abstract
Chromogranin A (CGA), which is cosecreted from the parathyroid gland with PTH in response to low extracellular calcium, can be processed to amino-terminal peptides that, in turn, inhibit PTH secretion. The synthetic peptide KCIVEVISDTLSKPSPMPVSKECFE [CGA-(16-40)] is active in inhibiting secretion from freshly isolated or cultured bovine parathyroid cells. Peptide analogs in which alanine is substituted for classes of residues between the two cysteines have been synthesized and tested for biological activity. Substitution of the lysine, serine, or threonine residues by alanines does not greatly diminish biological activity. However, when the prolines are replaced by alanines or when glutamic acid and aspartic acid are replaced by alanines, the peptides do not effectively inhibit PTH secretion. Tests of synthetic peptides in which the individual glutamate or aspartate residues have been replaced showed that glutamate 37, followed by aspartate 24, are more critical for biological activity. Further experiments have shown that residues 11-15 in the natural CGA sequence do not enhance the biological activity of CGA-(16-40), whereas adding residues 6-10 restores full biological activity compared to that of CGA-(1-40). Circular dichroism experiments with CGA-(16-40) and the alanine substitution analogs show significant differences only for the peptide in which the three prolines are replaced. The inactive peptide with two glutamic acids and one aspartic acid replaced by alanine residues has the same circular dichroism spectrum as some of the peptides that are fully active. The N-terminal CGA sequences may tolerate many changes without alteration of biological activity. However, there are specific amino acid residues that are required for biological function.
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Affiliation(s)
- R H Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Fields GB, Angeletti RH, Bonewald LF, Moore WT, Smith AJ, Stults JT, Williams LC. Correlation of cleavage techniques with side-reactions following solid-phase peptide synthesis. Techniques in Protein Chemistry 1995. [DOI: 10.1016/s1080-8914(06)80065-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Affiliation(s)
- K B Helle
- Department of Physiology, University of Bergen, Norway
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Angeletti RH, Aardal S, Serck-Hanssen G, Gee P, Helle KB. Vasoinhibitory activity of synthetic peptides from the amino terminus of chromogranin A. Acta Physiol Scand 1994; 152:11-9. [PMID: 7810329 DOI: 10.1111/j.1748-1716.1994.tb09780.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Naturally occurring amino terminal fragments of chromogranin A (CGA), the calcium-binding protein found in all endocrine secretory vesicles, have vasoinhibitory activity when tested in isolated segments of the endothelium-denuded human saphenous vein. Synthetic peptides corresponding to sequences within the first 76 residues of chromogranin A have been made and tested for biological activity. Full length vasostatin I (CGA1-76) (40 nM), but not the truncated vasostatin I, CGA1-40 (100 nM) mimics natural chromogranin A fragments in its inhibition of contractions induced by endothelin-1 (ET-1) in calcium containing medium. CGA1-40 (100 nM) mimics the inhibitory effect of the vasostatins on the contractions induced in the absence of extracellular calcium by high potassium and noradrenaline, but not by ET-1. The iodinated peptides both exhibit saturable binding in an aortic smooth muscle cell line, indicative of a single class of high affinity binding protein ('receptor' with an apparent KD of approximately 45 nM. This binding is not affected by endothelin-1. Iodinated peptides can be crosslinked to a single polypeptide in binding experiments performed on intact calf aortic smooth muscle cells.
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Affiliation(s)
- R H Angeletti
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461
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Abstract
The parathyroid gland responds to decreases in levels of extracellular calcium by increasing the secretion of both PTH and chromogranin-A (CGA) in approximately equal molar ratios. Because CGA has been suggested to be a precursor for biologically active peptides, we used primary cultures of bovine parathyroid cells to examine the effects of various peptides from CGA as well as analogous peptides from chromogranin-B (CGB) on PTH secretion. In concentrations from 10(-8)-10(-7) M, amino-terminal peptide CGA-(1-76) effectively inhibited the release of PTH in response to low extracellular calcium. Truncated analogs of this peptide, CGA-(1-40), CGB-(1-41), and CGA-(17-38) were also found to be active in the following order: CGA-(1-76) = CGA-(1-40) = CGB-(1-41) > CGA-(17-38). The biological activity of CGA-(1-40) was markedly reduced after reduction and alkylation, which resulted in disruption of the single disulfide bond between Cys17 and Cys38. Moreover, peptides derived from other regions of CGA and CGB, which included CGA-(403-428), CGB-(1-16), CGB-(316-326), and CGB-(635-657) were inactive. Pulse-chase experiments, using primary cultures of bovine parathyroid cells, revealed the presence of a CGA peptide in the culture medium that had the same amino-terminal sequence and mobility on sodium dodecyl sulfate-polyacrylamide gels as synthetic CGA-(1-76). Furthermore, in binding and cross-linking studies using intact parathyroid cells, CGA-(1-40) formed a single, covalently linked protein complex with a mol wt of 78,000. Formation of the protein complex could be completely inhibited in the presence of an excess of either CGB-(1-41) or CGA-(17-38). These results show that a naturally occurring amino-terminal peptide from CGA as well as shorter analogs can act as potent inhibitors of PTH secretion, and that their biological activity may be mediated through binding to a specific cell surface protein.
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Affiliation(s)
- J Russell
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461
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Joyce S, Kuzushima K, Kepecs G, Angeletti RH, Nathenson SG. Characterization of an incompletely assembled major histocompatibility class I molecule (H-2Kb) associated with unusually long peptides: implications for antigen processing and presentation. Proc Natl Acad Sci U S A 1994; 91:4145-9. [PMID: 8183884 PMCID: PMC43741 DOI: 10.1073/pnas.91.10.4145] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [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: 01/29/2023] Open
Abstract
We have identified two forms of a major histocompatibility complex (MHC) class I molecule, H-2Kb, distinguishable by specific antibodies through a study of a genetically engineered mouse cell line that overexpresses these molecules. One form, a complex associated with beta 2-microglobulin (native, beta 2m+ class I), is detectable by conformation-dependent antibodies. The other form, which remains after preclearing cell lysates of native class I, is only poorly, if at all, associated with beta 2-microglobulin (beta 2m- class I) and is detectable by an antiserum against the cytoplasmic tail region of H-2K molecules. Both forms are also present in normal cell lines. The affinity-purified native class I molecules bind short peptides (8 or 9 residues) and assemble tightly with beta 2-microglobulin. In striking contrast, the beta 2m- class I molecules bind peptides that are longer (> 15 residues) than those bound to native class I molecules. This finding is consistent with the recent evidence that peptides longer than 8-10 amino acid residues are transported into the endoplasmic reticulum and suggests the possibility of a control step for peptide presentation by MHC in which the incompletely processed peptides bind to the heavy chain and a selected fraction undergoes final processing and presentation on the cell surface.
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Affiliation(s)
- S Joyce
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461
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Joyce S, Tabaczewski P, Angeletti RH, Nathenson SG, Stroynowski I. A nonpolymorphic major histocompatibility complex class Ib molecule binds a large array of diverse self-peptides. J Exp Med 1994; 179:579-88. [PMID: 8294869 PMCID: PMC2191392 DOI: 10.1084/jem.179.2.579] [Citation(s) in RCA: 83] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Unlike the highly polymorphic major histocompatibility complex (MHC) class Ia molecules, which present a wide variety of peptides to T cells, it is generally assumed that the nonpolymorphic MHC class Ib molecules may have evolved to function as highly specialized receptors for the presentation of structurally unique peptides. However, a thorough biochemical analysis of one class Ib molecule, the soluble isoform of Qa-2 antigen (H-2SQ7b), has revealed that it binds a diverse array of structurally similar peptides derived from intracellular proteins in much the same manner as the classical antigen-presenting molecules. Specifically, we find that SQ7b molecules are heterodimers of heavy and light chains complexed with nonameric peptides in a 1:1:1 ratio. These peptides contain a conserved hydrophobic residue at the COOH terminus and a combination of one or more conserved residue(s) at P7 (histidine), P2 (glutamine/leucine), and/or P3 (leucine/asparagine) as anchors for binding SQ7b. 2 of 18 sequenced peptides matched cytosolic proteins (cofilin and L19 ribosomal protein), suggesting an intracellular source of the SQ7b ligands. Minimal estimates of the peptide repertoire revealed that at least 200 different naturally processed self-peptides can bind SQ7b molecules. Since Qa-2 molecules associate with a diverse array of peptides, we suggest that they function as effective presenting molecules of endogenously synthesized proteins like the class Ia molecules.
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Affiliation(s)
- S Joyce
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York 10461-1975
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50
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Helle KB, Marley PD, Angeletti RH, Aunis D, Galindo E, Small DH, Livett BG. Chromogranin A: secretion of processed products from the stimulated retrogradely perfused bovine adrenal gland. J Neuroendocrinol 1993; 5:413-20. [PMID: 7691355 DOI: 10.1111/j.1365-2826.1993.tb00502.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chromogranin A (CGA) is a member of a family of highly acidic proteins co-stored and co-secreted with adrenaline and noradrenaline in the adrenal medulla. A number of biologically active fragments of CGA (CGAFs) have been characterized including a group of small N-terminal fragments collectively named vasostatins due to their vascular inhibitory activity. In the present study, the release of CGAFs, including CGA N-terminal fragments, from the isolated, retrogradely perfused bovine adrenal gland, has been studied under basal conditions and during nerve stimulation and perfusion with acetylcholine. The CGAFs were characterized by SDS-PAGE followed by immunoblotting with antisera to specific sequences within the CGA molecule. Many different CGAFs were released during stimulation of the glands. Antisera to CGA1-40 and CGA44-76 detected a 7 kD protein whose release was increased during stimulation. This component co-migrated with synthetic CGA1-76, was not immunoreactive to antisera to CGA79-113 or CGA124-143, and was seen whether or not the serine protease inhibitor aprotinin was present in the perfusion medium. The release of an approximately 18 kD component, which stained with antisera to CGA1-40, CGA44-76 and CGA79-113, but not to chromostatin (CGA124-143), was also increased during stimulation. Components of 22 kD and larger were detected with antisera to chromostatin, but not with antisera to CGA1-40, CGA44-76 and CGA79-113. Two of these components of 22 to 24 kD were enhanced during nerve stimulation in the presence of aprotinin. The results indicate that processed chromogranin A fragments are secreted from the bovine adrenal medulla during stimulation of chromaffin cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- K B Helle
- Department of Biochemistry, University of Melbourne, Victoria, Australia
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