Block in nuclear localization of period protein by a second clock mutation, timeless

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Science  18 Mar 1994:
Vol. 263, Issue 5153, pp. 1606-1609
DOI: 10.1126/science.8128247


In wild-type Drosophila, the period protein (PER) is found in nuclei of the eyes and brain, and PER immunoreactivity oscillates with a circadian rhythm. The studies described here indicate that the nuclear localization of PER is blocked by timeless (tim), a second chromosome mutation that, like per null mutations, abolishes circadian rhythms. PER fusion proteins without a conserved domain (PAS) and some flanking sequences are nuclear in tim mutants. This suggests that a segment of PER inhibits nuclear localization in tim mutants. The tim gene may have a role in establishing rhythms of PER abundance and nuclear localization in wild-type flies.

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