Cyclic amp calmodulin as post-translational modulators of fruiting in coprinus cinereus
Date Issued
December 1, 1981
Author(s)
Ballou, Leslie Robert
Advisor(s)
Raymond W. Holton
Additional Advisor(s)
Ronald Petersen
Otto J. Schwarz
Jeffrey M. Becker
Abstract
Dikaryotic mycelia of Coprinus cinereus, when incubated in 12 hour alternating light-dark cycles on the appropriate defined media, will begin to differentiate fruit bodies in 6 days which will sporulate 5 days later. Mycelia incubated in continuous light or continuous darkness will not give rise to normal fruiting structures. In fruiting cultures a diurnal fluctuation of cAMP content associated with mycelial extracts was detected in which levels of the nucleotide increased during light exposures and decreased during dark exposures. The amplitude of cAMP fluctuations decreased with culture age on a dry weight basis. Continuous light incubated mycelia contained an initially higher level of cAMP than continuous dark incubated mycelia and in both cases levels of the nucleotide decreased with culture age. In general, the activities of glycogen phosphorylase, triacylglycerol lipase and protein kinase were negatively affected in the presence of high levels of cAMP. The activity associated with a Ca++-dependent modulator protein, now called calmodulin, was very low or absent in non-initiating cultures but high in the mycelia of fruiting cultures, especially 24 hours prior to the first sign of differentiation in alternating light-dark incubated cultures. Associated with the pre-initiation increase in calmodulin activity was an increase in the phosphorylation of histone by kinases associated with crude mycelial extracts. A comparison of the activities of the post-translational modulators examined during the differentiation of Coprinus indicated that a decreasing, diurnally fluctuating pattern of cAMP content, high calmodulin and histone phosphorylation activity were biochemical events that were critical to the initiation of the differentiation of fruit bodies.
Degree
Doctor of Philosophy
Major
Botany
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Thesis81b.B254.pdf
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