A Possible Second Role for Calmodulin in Biological Clock-Controlled Processes of Euglena

AUTOR(ES)

Lonergan, Thomas A.

RESUMO

The response of the Euglena gracilis (Klebs strain Z) photosynthesis circadian rhythm to three calmodulin antagonists was examined. In the presence of an antagonist, the photosynthetic reactions were uncoupled from the biological clock. Instead of the highly predictable rhythmic pattern characteristic of a biological clock-controlled circadian rhythm, the photosynthetic rate appears to be influenced by the light/dark cycle. The rate of O2 evolution increases throughout the light portion of the cycle and does not decrease until the cells are exposed to darkness. Shortterm exposure to a calmodulin antagonist (2 hour pulses) failed to cause phase shifts in the timing of the rhythm. This suggests that calmodulin is not part of the clock controlling photosynthesis and that it has a clock-related role different from that reported for the cell division rhythm in Euglena.

Documentos Relacionados

• Neurospora crassa clock-controlled genes are regulated at the level of transcription.
• Possible Involvement of Leaf Gibberellins in the Clock-Controlled Expression of XSP30, a Gene Encoding a Xylem Sap Lectin, in Cucumber Roots1
• The interplay of light and the circadian clock. Independent dual regulation of clock-controlled gene ccg-2(eas).
• Circadian clock-controlled genes isolated from Neurospora crassa are late night- to early morning-specific
• Neurospora Clock-Controlled Gene 9 (ccg-9) Encodes Trehalose Synthase: Circadian Regulation of Stress Responses and Development