The authors analyzed circadian features of two period-lacZ (per-lacZ) fusion genes in transgenic strains of Drosophila. Both genes manifest circadian fluctuations of mRNA levels, but fluctuations of only the larger chimeric protein are apparent. Fusion protein cycling is indistinguishable from the behavior of wild-type per protein (PER), including apparent temporal regulation of phosphorylation state. Several arguments indicate that the difference in the two constructs is proper regulation at the level of protein turnover: the smaller protein has much higher levels; a β-galactosidase degradation product is visible in both strains but fails to manifest cycling, presumably due to a long half-life; and only the noncycling proteins accumulate as a function of adult age. The large cycling fusion protein also undergoes modest cycling in an arrhythmic per01 background. This is light dependent, resembles the regulation of the timeless protein (TIM) by light, and reflects a documented fusion protein-TIM interaction. The results are discussed with respect to the posttranscriptional regulation that is necessary for proper cycling of both PER and TIM as well as for clock function.
Baylies Mk, Weiner L., Vosshall Lb, Saez L., and Young Mw (1993) Genetic, molecular, and cellular studies of the per locus and its products in Drosophila melanogaster. In Molecular Genetics of Biological Rhythms, MW Young, ed, pp 123-153, Marcel Dekker, New York.
2.
Brandes C., Plautz Jd, Stanewsky R., Jamison Cf, Straume M., Wood Kv, Kay Sa, and Hall Jc ( 1996) Novel features of Drosophila period transcription revealed by real-time luciferase reporting. Neuron16:687-692.
3.
Curtin K., Huang Zj, and Rosbash M. (1995) Temporally regulated nuclear entry of the Drosophila period protein contributes to the circadian clock. Neuron14:365-372.
4.
Edery I., Rutila Je, and Rosbash M. (1994a) Phase shifting of the circadian clock by induction of the Drosophila period protein. Science263:237-240.
5.
Edery I., Zwiebel Lj, Dembinska Me, and Rosbash M. (1994b) Temporal phosphorylation of the Drosophila period protein. Proc Natl Acad Sci USA91:2260-2264.
6.
Edmunds Ln Jr (1988) Cellular and Molecular Bases of Biological Clocks: Models and Mechanisms for Circadian Timekeeping, Springer-Verlag , New York.
7.
Frisch B., Hardin Pe, Hamblen-Coyle MJ, Rosbash M., and Hall Jc (1994) A promoterless DNA fragment from the period locus rescues behavioral rhythmicity and mediates cyclical gene expression in a restricted subset of the Drosophila nervous system. Neuron12:555-570.
8.
Gekakis N., Saez L., Delahaye-Brown A-M., Myers Mp, Sehgal A., Young Mw, and Weitz Cj (1995) Isolation of timeless by PER protein interactions: Defective interaction between timeless protein and long-period mutant PERL . Science270:811-815.
9.
Hardin Pe, Hall Jc, and Rosbash M. (1993) Circadian cycling of protein and mRNA from Drosophila melanogaster's period gene. In Molecular Genetics of Biological Rhythms, MW Young, ed, pp 155-170, Marcel Dekker, New York.
10.
Hardin Pe, Hall Jc, and Rosbash M. (1992) Circadian oscillations in period gene mRNA levels are transcriptionally regulated. Proc Natl Acad Sci USA89:11711-11715.
11.
Hardin Pe, Hall Jc, and Rosbash M. (1990) Feedback of the Drosophila period gene product on circadian cycling of its messenger RNA levels. Nature343:536-540.
12.
Hastings Jw and Schweiger H-G. (1976) The Molecular Basis of Circadian Rhythms, Dahlem Konferenzen, Berlin.
13.
Hunter-Ensor M., Ousley A., and Sehgal A. (1996) Regulation of the Drosophila protein timeless suggests a mechanism for resetting the circadian clock by light. Cell84:677-685.
14.
Kellerman Ka, Mattson Dm, and Duncan I. (1990) Mutations affecting the stability of the fushi tarazu protein of Drosophila. Genes Dev4:1936-1950.
15.
Lee C., Parikh V., Itsukaichi T., Bae K., and Edery I. (1996) Resetting the Drosophila clock by photic regulation of PER and a PER-TIM complex. Science271:1740-1744.
16.
Liu X., Lorenz L., Yu Q., Hall Jc, and Rosbash M. (1988) Spatial and temporal expression of the period gene in Drosophila melanogaster. Genes Dev2:228-238.
17.
Liu X., Yu Q., Huang Z., Zwiebel Lj, Hall Jc, and Rosbash M. (1991) The strength and periodicity of Drosophila melanogaster circadian rhythms are differentially affected by alterations in period gene expression. Neuron6:753-766.
18.
Liu X., Zwiebel Lj, Hinton D., Benzer S., Hall Jc, and Rosbash M. (1992) The period gene encodes a predominantly nuclear protein in adult Drosophila. J Neurosci12:2735-2744.
19.
Monsma S., Ard R., Lis J., and Wolfner Mf (1988) Localized heat-shock induction in Drosophila melanogaster . J Exp Zool247:279-284.
20.
Murray Aw (1993) Turning on mitosis. Current Biol3:291-293.
21.
Myers Mp, Wager-Smith K., Rothenfluh-Hilfiker A., and Young Mw (1996) Light-induced degradation of TIMELESS and entrainment of the Drosophila circadian clock. Science271:1736-1740.
22.
Nurse P. (1992) Eukaryotic cell-cycle control. Biochem Soc Trans20:239-242.
23.
Price Jl, Dembinska Me, Young Mw, and Rosbash M. (1995) Suppression of PERIOD protein abundance and circadian cycling by the Drosophila clock mutation timeless. EMBO J14:4044-4049.
24.
Reppert Sm, Tsai T., Foca Al, and Sauman I. (1994) Cloning of a structural and functional homolog of the circadian clock gene period from the giant silkmoth Antheraea pernyi . Neuron13:1167-1176.
25.
Robertson Hm, Preston Cr, Phillis Rw, Johnson-Schlitz Dm, Benz Wk, and Engels Wr (1988) A stable genomic source of P element transposase in Drosophila melanogaster. Genetics118:461-470.
26.
Rosbash M. and Hall Jc (1989) The molecular biology of circadian rhythms. Neuron3:387-398.
27.
Rutila Je, Zeng H., Le M., Curtin Kd, Hall Jc, and Rosbash M. (1996) The timSL mutant of the Drosophila rhythm gene timeless manifests allele-specific interactions with period gene mutants . Neuron17:921-929.
28.
Sehgal A., Price Jl, Man B., and Young Mw (1994) Loss of circadian behavioral rhythms and per RNA oscillations in the Drosophila mutant timeless. Science263:1603-1606.
29.
Sehgal A., Rothenfluh-Hilfiker A., Hunter-Ensor M., Chen Y., Myers M., and Young Mw (1995) Circadian oscillations and autoregulation of timeless RNA. Science270:808-810.
30.
Simon Ja, Sutton Ca, Lobell Rb, Glaser Rl, and Lis Jt (1985) Determinants of heat shock-induced chromosome puffing. Cell40:805-817.
31.
Stanewsky R., Frisch B., Brandes C., Hamblen-Coyle Mj, Rosbash M., and Hall Jc (1997) Temporal and spatial expression patterns of transgenes containing increasing amounts of the Drosophila clock gene period and the lacZ reporter: Mapping elements involved in circadian cycling. J Neurosci17:676-696.
32.
Takahashi Js (1991) Circadian rhythms: From gene expression to behavior . Current Opin Neurobiol1:556-561.
33.
Vosshall Lb, Price Jl, Sehgal A., Saez L., and Young Mw (1994) Specific block in nuclear localization of period protein by a second clock mutation, timeless. Science263:1606-1609.
34.
Vosshall Lb and Young Mw (1995) Circadian rhythms in Drosophila can be driven by period expression in a restricted group of central brain cells. Neuron15:345-360.
35.
Wuarin J., Falvey E., Lavery D., Talbot D., Schmidt E., Ossipow V., Fonjallaz P., and Schibler U. (1992) The role of the transcriptional activator protein DBP in circadian liver gene expression. J Cell Sci (Suppl) 16:123-127.
36.
Yaglom J., Linskens Mhk, Sadis S., Rubin Dm, Futcher B., and Finley D. (1995) p34Cdc28-mediated control of Cln3 cyclin degradation . Mol Cell Biol15:731-741.
37.
Zeng H., Hardin Pe, and Rosbash M. (1994) Constitutive overexpression of the Drosophila period protein inhibits period mRNA cycling. EMBO J13:3590-3598.
38.
Zeng H., Qian Z., Myers Mp, and Rosbash M. (1996) A light-entrainment mechanism for the Drosophila circadian clock. Nature380:129-135.
39.
Zerr Dm, Hall Jc, Rosbash M., and Siwicki Kk (1990) Circadian fluctuations of period protein immunoreactivity in the CNS and the visual system of Drosophila. J Neurosci10:2749-2762.
40.
Zwiebel Lj, Hardin Pe, Liu X., Hall Jc, and Rosbash M. (1991) A post-transcriptional mechanism contributes to circadian cycling of per β-galactosidase fusion protein. Proc Natl Acad Sci USA88:3882-3886.
