Energy requirement for liquid holding recovery from UV- and DEB-induced damage in rad mutants of Saccharomyces cerevisiae
Zaborowska, D.; Swietlińska, Z.; Haładus, E.; Zuk, J.
Acta Microbiologica Polonica 29(1): 5-19
1980
ISSN/ISBN: 0137-1320 PMID: 6155053 Document Number: 160854
Respiratory deficient (rho o) strains respond to liquid holding in buffer alone with a sharp decrease of cell survival. In buffer with 0.02% glucose rho o strains behave similarly as rho+ strains. After UV or DEB inactivation rho o strains derived from rho+ rad mutants capable of LHR in buffer alone, manifest this capacity in glucose buffer. In some respiratory proficient rad mutants LHR is enhanced or induced by holding in glucose buffer, e.g. DEB inactivated rad3, rad6 and rad14. In such mutants the number of mitochondrial profiles was found to be 3 to 4 times lower than in the wild-type RAD or in rad mutants with LHR insensitive to glucose. This suggests that mutants with glucose-enhanced LHR are defective in energy metabolism and require exogenous energy supply for initiation of liquid holding repair capacity. In UV-irradiated JG-1 (rad1-1), rad3 and rad11 as well as in DEB-inactivated rad7, rad11, rad19 and rad20 the inability of LHR is a constitutive phenomenon and cannot be overcome by exogenous energy supply.