PER protein interactions and temperature compensation of a circadian clock in Drosophila

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Science  24 Feb 1995:
Vol. 267, Issue 5201, pp. 1169-1172
DOI: 10.1126/science.7855598


The periods of circadian clocks are relatively temperature-insensitive. Indeed, the perL mutation in the Drosophila melanogaster period gene, a central component of the clock, affects temperature compensation as well as period length. The per protein (PER) contains a dimerization domain (PAS) within which the perL mutation is located. Amino acid substitutions at the perL position rendered PER dimerization temperature-sensitive. In addition, another region of PER interacted with PAS, and the perL mutation enhanced this putative intramolecular interaction, which may compete with PAS-PAS intermolecular interactions. Therefore, temperature compensation of circadian period in Drosophila may be due in part to temperature-independent PER activity, which is based on competition between inter- and intramolecular interactions with similar temperature coefficients.

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