Molecular Analysis of a Chloroplast Protein Import          Intermediate
{'Code': '08070600', 'Directorate': {'Abbreviation': 'BIO', 'LongName': 'Direct For Biological Sciences'}, 'Division': {'Abbreviation': 'MCB', 'LongName': 'Div Of Molecular and Cellular Bioscience'}}
{'SignBlockName': 'Maryanna P. Henkart', 'PO_EMAI': None, 'PO_PHON': None}
The mechanism of protein translocation across cellular membranes is not         well understood.  This proposal will focus on the translocation of              proteins across the two membranes of the chloroplast envelope during the        course of protein import into pea chloroplasts.  It is the goal of this         proposal to define and characterize a protease resistant fragment that          is trapped when the organelles are exposed to low temperature or when           photophosphorylation is blocked by the uncoupler nigericin.  Three              alternatives have been proposed to account for the formation of a               protease resistant import intermediate.  These are: A) a two step               process in which the precursor successively crosses first the outer             envelope membrane and then the inner envelope membrane; B) and                  alternative two step process in which the precursor spans the                   intermembrane space  while crossing both the outer and inner envelope           membranes; and C) a one step translocation mechanism at envelope                membrane contact sites.                                                                                                                                         We propose to test these alternative import pathways in an in vitro             chloroplast import assay.  For this assay, specific mRNAs encoding the          small subunit of ribulose 1,5-bisphosphate carboxylase precursor (prSS)         will be expressed by in vitro transcription from plasmids.  The                 precursor proteins will be translated in a cell free wheat germ                 translation system.  By modulating the temperature of import, we will           define the temperatures at which the protease protected fragment                accumulates as well as the permissive temperature range of import.  The         trapped intermediate will be analyzed to determine: a) which domain or          region of the precursor is protected from proteolysis; b) in which              chloroplast compartment the precursor fragment is protected; c) if other        chloroplast precursors follow a similar import pathway; and; d) the             biochemical basis of import inhibition by low temperature and nigericin.        It is expected that the results of this study will not only serve as a          model system for other protein translocation pathways in the cell, but          will also expand our understanding of chloroplast biogenesis.
{'FirstName': 'Alan', 'LastName': 'Friedman', 'PI_MID_INIT': 'L', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'Alan L Friedman', 'EmailAddress': None, 'NSF_ID': '000471374', 'StartDate': '04/01/1989', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'Marquette University', 'CityName': 'MILWAUKEE', 'ZipCode': '532332244', 'PhoneNumber': '4142887200', 'StreetAddress': '313 N 13TH ST', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'Wisconsin', 'StateCode': 'WI', 'CONGRESSDISTRICT': '04', 'CONGRESS_DISTRICT_ORG': 'WI04', 'ORG_UEI_NUM': 'HKJCKTFJNBM7', 'ORG_LGL_BUS_NAME': 'MARQUETTE UNIVERSITY', 'ORG_PRNT_UEI_NUM': None}
{'Name': None, 'CityName': None, 'StateCode': None, 'ZipCode': None, 'StreetAddress': None, 'CountryCode': None, 'CountryName': None, 'StateName': None, 'CountryFlag': None, 'CONGRESSDISTRICT': None, 'CONGRESS_DISTRICT_PERF': '""'}
[{'Code': '1114', 'Text': 'Cellular Dynamics and Function'}, {'Code': '9145', 'Text': 'SPECIAL PROGRAMS-RESERVE'}]
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8819198.xml'}