Enzymes Involved in the Regulation of Nitrogen Metabolism
{'Code': '08070800', 'Directorate': {'Abbreviation': 'BIO', 'LongName': 'Direct For Biological Sciences'}, 'Division': {'Abbreviation': 'MCB', 'LongName': 'Div Of Molecular and Cellular Bioscience'}}
{'SignBlockName': 'Robert Uffen', 'PO_EMAI': None, 'PO_PHON': None}
This project supports research on the regulation of nitrogen                    metabolism by ADP-ribosylation of nitrogenase and other                         proteins in the photosynthetic bacterium Rhodospirillum                         rubrum.  The system is unique in that the first two enzymes                     of the nitrogen assimilatory pathway are regulated by                           separate covalent modification cycles:  dinitrogenase                           reductase is reversibly ADP-ribosylated and glutamine                           synthetase is reversibly adenylylated.  Recently, it was                        discovered that R. rubrum glutamine synthetase can also be                      ADP-ribosylated in vitro and this suggests a mechanism by                       which the two cascades can be coordinated in vivo.  In                          addition to the dinitrogenase reductase component of the                        nitrogenase complex, the R. rubrum ADP-ribosyl transferase                      will ADP-ribosylate dinitrogenase reductases from other                         organisms.  Biochemical studies have shown that these                           alternate targets have distinctly different requirements for                    modification.  The genes for these alternate targets will be                    transfered to R. rubrum so that a biochemical analysis of                       their properties as targets in vivo can be made.  Results                       from these studies will delimit the requirements for ADP-                       ribosylation of dinitrogenase reductase in vivo.%%%                                                                                                             Organisms must adapt their metabolism to respond to their                       environment.  Microorganisms, in particular, are subject to                     rapid and divergent changes in their environment.                               Rhodospirillum rubrum is remarkable in its ability grow under                   drastically different conditions photosynthetically,                            fermentatively and by respiration.  It is capable of using                      both very simple carbon sources, such as carbon dioxide and                     carbon monoxide, and a variety of complex carbon sources.  It                   is capable of assimilating nitrogen in the form of ammonia                      nitrogen and also possesses the ability to control metabolism                   by reversible covalent modification of certain enzymes.                         Dinitrogenase reductase of the nitrogenase enzyme system is                     reversibly modified by adenosine diphosphoribose, glutamine                     synthetase is regulated by adenylylation and perhaps by ADP-                    ribosylation, and it is likely that other metabolic pathways                    are regulated by these mechanisms.  Thus, the study of                          nitrogen assimilation in R. rubrum offers the opportunity to                    study the interaction of separate regulatory cascades which                     must respond to some of the same stimuli.  This research will                   provide for an understanding of the relationship of these                       cascades to each other and their integration into metabolism                    in the cell.***//
{'FirstName': 'Paul', 'LastName': 'Ludden', 'PI_MID_INIT': 'W', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Paul W Ludden', 'EmailAddress': 'ludden@biochem.wisc.edu', 'NSF_ID': '000405876', 'StartDate': '07/15/1989', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of Wisconsin-Madison', 'CityName': 'MADISON', 'ZipCode': '537151218', 'PhoneNumber': '6082623822', 'StreetAddress': '21 North Park Street', 'StreetAddress2': 'Suite 6301', 'CountryName': 'United States', 'StateName': 'Wisconsin', 'StateCode': 'WI', 'CONGRESSDISTRICT': '02', 'CONGRESS_DISTRICT_ORG': 'WI02', 'ORG_DUNS_NUM': '161202122', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF WISCONSIN SYSTEM', 'ORG_PRNT_DUNS_NUM': '041188822'}
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[{'Code': '1168', 'Text': None}, {'Code': '9145', 'Text': 'SPECIAL PROGRAMS-RESERVE'}]
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8821820.xml'}