caa a22 4500 465826261 CHVBK 20180323112150.0 cr unu---uuuuu 170327e19901101xx s 000 0 eng 10.1007/BF00691715 doi (NATIONALLICENCE)springer-10.1007/BF00691715 On the role of Ca2+-calmodulin-dependent and cAMP-dependent protein phosphorylation in the circadian rhythm of Neurospora crassa [Elektronische Daten] [D. Techel, G. Gebauer, W. Kohler, T. Braumann, B. Jastorff, L. Rensing] Summary: Pulses of some Ca2+ channel blockers (dantrolene, Co2+, nifedipine) and calmodulin inhibitors (chlorpromazine) lead to medium (maximally 5-9 h) phase shifts of the circadian conidiation rhythm ofNeurospora crassa. Pulses of high Ca2+, or of low Ca2+, a Ca2+ ionophore (A23187) together with Ca2+, and other Ca2+ channel blockers (La3+, diltiazem), however, caused only minor phase shifts. The effect of these substances (A 23187) and of different temperatures on the Ca2+ release from isolated vacuoles was analyzed by using the fluorescent dye Fura-2. A 23187 and higher temperatures increased the release drastically, whereas dantrolene decreased the permeation of Ca2+ (Cornelius et al., 1989). Pulses of 8-PCTP-cAMP, IBMX and of the cAMP antagonist RP-cAMPS, also caused medium (maximally 6-9 h) phase shifts of the conidiation rhythm. The phase response curve of the agonist was almost 180° out of phase with the antagonist PRC. In spite of some variability in the PRCs of these series of experiments all showed maximal shifts during ct 0-12. The variability of the response may be due to circadian changes in the activity of phosphodiesterases: After adding cAMP to mycelial extracts HPLC analysis of cAMP metabolites showed significant differences during a circadian period with a maximum at ct 0. Protein phosphorylation was tested mainly in an in vitro phosphorylation system (with35S-thio γ-ATP). The results showed circadian rhythmic changes predominantly in proteins of 47/48 kDa. Substances and treatments causing phase-shifts of the conidiation rhythm also caused changes in the phosphorylation of these proteins: an increase was observed when Ca2+ or cAMP were added, whereas a decrease occurred upon addition of a calmodulin inhibitor (TFP) or pretreatment of the mycelia with higher (42° C) temperatures. Altogether, the results indicate that Ca2+-calmodulin-dependent and cAMP-dependent processes play an important, but perhaps not essential, role in the clock mechanism ofNeurospora. Ca2+ calmodulin and the phosphorylation state of the 47/48-kDa proteins may have controlling or essential functions for this mechanism. Springer-Verlag, 1990 Neurospora nationallicence Calcium nationallicence cAMP nationallicence Protein phosphorylation nationallicence Circadian rhythm nationallicence Techel D. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut Gebauer G. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut Kohler W. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut Braumann T. Department of Chemistry, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut Jastorff B. Department of Chemistry, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut Rensing L. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut Journal of Comparative Physiology B Springer-Verlag 159/6(1990-11-01), 695-706 0174-1578 159:6<695 1990 159 360 https://doi.org/10.1007/BF00691715 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00691715 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Techel D. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut NATIONALLICENCE 700 1- Gebauer G. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut NATIONALLICENCE 700 1- Kohler W. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut NATIONALLICENCE 700 1- Braumann T. Department of Chemistry, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut NATIONALLICENCE 700 1- Jastorff B. Department of Chemistry, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut NATIONALLICENCE 700 1- Rensing L. Department of Biology, University of Bremen, D-2800, Bremen, Federal Republic of Germany aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer-Verlag 159/6(1990-11-01), 695-706 0174-1578 159:6<695 1990 159 360 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer