Mechanism and Regulation of the Transport Processes         Responsible for the Extracellular Current Pattern Formation in Chara and Nitella
{'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 proposed research will address the characterization of the                  membrane transport processes, located in the plasma membrane of                 Chara and Nitella, that generate the extracellular current                      pattern along the length of these giant algal cells.  Based on                  preliminary current-voltage profiles, obtained when these                       extracellular currents were in the light-activated condition, and               on vibrating probe measurements of these currents obtained during               pH pulse experiments, the hypothesis has been proposed that the                 acid and alkaline bands are generated by a Class II transport                   system.  An extensive biophysical test of this hypothesis will                  now be conducted using state of the art current-voltage                         measurements in combination with kinetic modelling.  For these                  studies a new computer-operated 2-dimensional vibrating probe                   system will provide important information on the cellular                       mechanisms responsible for temporal and spatial control over the                putative Class II transporter.  Ion selective microelectrodes                   will also be used to record light-induced changes in cytoplasmic                calcium and pH in experiments aimed at elucidating the                          biochemical processes responsible for the time dependent                        activation of these membrane transport processes following                      illumination.  The hypothesis will be tested that dark-induced                  inactivation of transport is effected through a coupled reaction                involving an increase in cytoplasmic calcium which activates                    calcium-calmodulin followed by calcium-calmodulin activation of a               protein phosphorylase which inactivates the hydrogen ion                        transport system by phosphorylation.  The involvement of a                      protein phosphatase in reactivation will also be investigated.                  Finally, the involvement of protein synthesis in the regulation                 process will be further investigated using inhibitors of 70S                    (chloroplast and mitochondria) and 80S (cytoplasmic) protein                    synthesis.                                                                                                                                                      The giant algae Chara and Nitella have been the subject of                      physiological studies for many years.  The large size of their                  cells and the light dependent patterns of electrical current that               they generate make them an excellent system in which to study the               membrane transport processes underlying cellular electrical                     phenomena.  The results of this research using state of the art                 biophysical techniques should greatly enhance our understanding                 of the physiology of plant cell membranes.
{'FirstName': 'William', 'LastName': 'Lucas', 'PI_MID_INIT': 'J', 'PI_SUFX_NAME': None, 'PI_FULL_NAME': 'William J Lucas', 'EmailAddress': 'wjlucas@ucdavis.edu', 'NSF_ID': '000447389', 'StartDate': '02/01/1989', 'EndDate': None, 'RoleCode': 'Principal Investigator'}
{'Name': 'University of California-Davis', 'CityName': 'DAVIS', 'ZipCode': '956186153', 'PhoneNumber': '5307547700', 'StreetAddress': '1850 RESEARCH PARK DR STE 300', 'StreetAddress2': None, 'CountryName': 'United States', 'StateName': 'California', 'StateCode': 'CA', 'CONGRESSDISTRICT': '04', 'CONGRESS_DISTRICT_ORG': 'CA04', 'ORG_UEI_NUM': 'TX2DAGQPENZ5', 'ORG_LGL_BUS_NAME': 'UNIVERSITY OF CALIFORNIA, DAVIS', 'ORG_PRNT_UEI_NUM': 'NUDGYLBB4S99'}
{'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'}
{'url': 'https://www.nsf.gov/awardsearch/download?DownloadFileName=1988&All=true', 'xml': '8816077.xml'}