Abstract
The Drosophila extra sex combs (esc) protein, a member of the Polycomb group (PcG), is a transcriptional repressor of homeotic genes. Genetic studies have shown that esc protein is required in early embryos at about the time that other PcG proteins become engaged in homeotic gene repression. The esc protein consists primarily of multiple copies of the WD repeat, a motif that has been implicated in protein-protein interaction. To further investigate the domain organization of esc protein, we have isolated and characterized esc homologs from divergent insect species. We report that esc protein is highly conserved in housefly (72% identical to Drosophila esc), butterfly (55% identical), and grasshopper (56% identical). We show that the butterfly homolog provides esc function in Drosophila, indicating that the sequence similarities reflect functional conservation. Homology modeling using the crystal structure of another WD repeat protein, the G-protein beta-subunit, predicts that esc protein adopts a beta-propeller structure. The sequence comparisons and modeling suggest that there are seven WD repeats in esc protein which together form a seven-bladed beta-propeller. We locate the conserved regions in esc protein with respect to this predicted structure. Site-directed mutagenesis of specific loops, predicted to extend from the propeller surface, identifies conserved parts of esc protein required for function in vivo. We suggest that these regions might mediate physical interaction with esc partner proteins.
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- Akasaka T., Kanno M., Balling R., Mieza M. A., Taniguchi M., Koseki H. A role for mel-18, a Polycomb group-related vertebrate gene, during theanteroposterior specification of the axial skeleton. Development. 1996 May;122(5):1513–1522. doi: 10.1242/dev.122.5.1513. [DOI] [PubMed] [Google Scholar]
- Beachy P. A., Helfand S. L., Hogness D. S. Segmental distribution of bithorax complex proteins during Drosophila development. Nature. 1985 Feb 14;313(6003):545–551. doi: 10.1038/313545a0. [DOI] [PubMed] [Google Scholar]
- Brown N. H., Kafatos F. C. Functional cDNA libraries from Drosophila embryos. J Mol Biol. 1988 Sep 20;203(2):425–437. doi: 10.1016/0022-2836(88)90010-1. [DOI] [PubMed] [Google Scholar]
- Carroll S. B., Gates J., Keys D. N., Paddock S. W., Panganiban G. E., Selegue J. E., Williams J. A. Pattern formation and eyespot determination in butterfly wings. Science. 1994 Jul 1;265(5168):109–114. doi: 10.1126/science.7912449. [DOI] [PubMed] [Google Scholar]
- Carroll S. B., Laymon R. A., McCutcheon M. A., Riley P. D., Scott M. P. The localization and regulation of Antennapedia protein expression in Drosophila embryos. Cell. 1986 Oct 10;47(1):113–122. doi: 10.1016/0092-8674(86)90372-7. [DOI] [PubMed] [Google Scholar]
- Celniker S. E., Keelan D. J., Lewis E. B. The molecular genetics of the bithorax complex of Drosophila: characterization of the products of the Abdominal-B domain. Genes Dev. 1989 Sep;3(9):1424–1436. doi: 10.1101/gad.3.9.1424. [DOI] [PubMed] [Google Scholar]
- Chasan R., Jin Y., Anderson K. V. Activation of the easter zymogen is regulated by five other genes to define dorsal-ventral polarity in the Drosophila embryo. Development. 1992 Jun;115(2):607–616. doi: 10.1242/dev.115.2.607. [DOI] [PubMed] [Google Scholar]
- Chen L., Mathews F. S., Davidson V. L., Huizinga E. G., Vellieux F. M., Hol W. G. Three-dimensional structure of the quinoprotein methylamine dehydrogenase from Paracoccus denitrificans determined by molecular replacement at 2.8 A resolution. Proteins. 1992 Oct;14(2):288–299. doi: 10.1002/prot.340140214. [DOI] [PubMed] [Google Scholar]
- Coré N., Bel S., Gaunt S. J., Aurrand-Lions M., Pearce J., Fisher A., Djabali M. Altered cellular proliferation and mesoderm patterning in Polycomb-M33-deficient mice. Development. 1997 Feb;124(3):721–729. doi: 10.1242/dev.124.3.721. [DOI] [PubMed] [Google Scholar]
- Curtis D., Apfeld J., Lehmann R. nanos is an evolutionarily conserved organizer of anterior-posterior polarity. Development. 1995 Jun;121(6):1899–1910. doi: 10.1242/dev.121.6.1899. [DOI] [PubMed] [Google Scholar]
- Franke A., DeCamillis M., Zink D., Cheng N., Brock H. W., Paro R. Polycomb and polyhomeotic are constituents of a multimeric protein complex in chromatin of Drosophila melanogaster. EMBO J. 1992 Aug;11(8):2941–2950. doi: 10.1002/j.1460-2075.1992.tb05364.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ganfornina M. D., Sánchez D., Bastiani M. J. Lazarillo, a new GPI-linked surface lipocalin, is restricted to a subset of neurons in the grasshopper embryo. Development. 1995 Jan;121(1):123–134. doi: 10.1242/dev.121.1.123. [DOI] [PubMed] [Google Scholar]
- Gutjahr T., Frei E., Spicer C., Baumgartner S., White R. A., Noll M. The Polycomb-group gene, extra sex combs, encodes a nuclear member of the WD-40 repeat family. EMBO J. 1995 Sep 1;14(17):4296–4306. doi: 10.1002/j.1460-2075.1995.tb00104.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hu J., Xu Y., Schappert K., Harrington T., Wang A., Braga R., Mogridge J., Friesen J. D. Mutational analysis of the PRP4 protein of Saccharomyces cerevisiae suggests domain structure and snRNP interactions. Nucleic Acids Res. 1994 May 11;22(9):1724–1734. doi: 10.1093/nar/22.9.1724. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ito N., Phillips S. E., Stevens C., Ogel Z. B., McPherson M. J., Keen J. N., Yadav K. D., Knowles P. F. Novel thioether bond revealed by a 1.7 A crystal structure of galactose oxidase. Nature. 1991 Mar 7;350(6313):87–90. doi: 10.1038/350087a0. [DOI] [PubMed] [Google Scholar]
- Jones R. S., Gelbart W. M. The Drosophila Polycomb-group gene Enhancer of zeste contains a region with sequence similarity to trithorax. Mol Cell Biol. 1993 Oct;13(10):6357–6366. doi: 10.1128/mcb.13.10.6357. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Karch F., Bender W., Weiffenbach B. abdA expression in Drosophila embryos. Genes Dev. 1990 Sep;4(9):1573–1587. doi: 10.1101/gad.4.9.1573. [DOI] [PubMed] [Google Scholar]
- Kaufman P. D., Kobayashi R., Kessler N., Stillman B. The p150 and p60 subunits of chromatin assembly factor I: a molecular link between newly synthesized histones and DNA replication. Cell. 1995 Jun 30;81(7):1105–1114. doi: 10.1016/s0092-8674(05)80015-7. [DOI] [PubMed] [Google Scholar]
- Kaufman T. C., Lewis R., Wakimoto B. Cytogenetic Analysis of Chromosome 3 in DROSOPHILA MELANOGASTER: The Homoeotic Gene Complex in Polytene Chromosome Interval 84a-B. Genetics. 1980 Jan;94(1):115–133. doi: 10.1093/genetics/94.1.115. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Komachi K., Redd M. J., Johnson A. D. The WD repeats of Tup1 interact with the homeo domain protein alpha 2. Genes Dev. 1994 Dec 1;8(23):2857–2867. doi: 10.1101/gad.8.23.2857. [DOI] [PubMed] [Google Scholar]
- Krumlauf R. Hox genes in vertebrate development. Cell. 1994 Jul 29;78(2):191–201. doi: 10.1016/0092-8674(94)90290-9. [DOI] [PubMed] [Google Scholar]
- Lewis E. B. A gene complex controlling segmentation in Drosophila. Nature. 1978 Dec 7;276(5688):565–570. doi: 10.1038/276565a0. [DOI] [PubMed] [Google Scholar]
- Lonie A., D'Andrea R., Paro R., Saint R. Molecular characterisation of the Polycomblike gene of Drosophila melanogaster, a trans-acting negative regulator of homeotic gene expression. Development. 1994 Sep;120(9):2629–2636. doi: 10.1242/dev.120.9.2629. [DOI] [PubMed] [Google Scholar]
- Martin E. C., Adler P. N. The Polycomb group gene Posterior Sex Combs encodes a chromosomal protein. Development. 1993 Feb;117(2):641–655. doi: 10.1242/dev.117.2.641. [DOI] [PubMed] [Google Scholar]
- Moazed D., O'Farrell P. H. Maintenance of the engrailed expression pattern by Polycomb group genes in Drosophila. Development. 1992 Nov;116(3):805–810. doi: 10.1242/dev.116.3.805. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Müller J., Gaunt S., Lawrence P. A. Function of the Polycomb protein is conserved in mice and flies. Development. 1995 Sep;121(9):2847–2852. doi: 10.1242/dev.121.9.2847. [DOI] [PubMed] [Google Scholar]
- Neer E. J., Schmidt C. J., Nambudripad R., Smith T. F. The ancient regulatory-protein family of WD-repeat proteins. Nature. 1994 Sep 22;371(6495):297–300. doi: 10.1038/371297a0. [DOI] [PubMed] [Google Scholar]
- Neer E. J., Smith T. F. G protein heterodimers: new structures propel new questions. Cell. 1996 Jan 26;84(2):175–178. doi: 10.1016/s0092-8674(00)80969-1. [DOI] [PubMed] [Google Scholar]
- Paro R., Zink B. The Polycomb gene is differentially regulated during oogenesis and embryogenesis of Drosophila melanogaster. Mech Dev. 1993 Jan;40(1-2):37–46. doi: 10.1016/0925-4773(93)90086-d. [DOI] [PubMed] [Google Scholar]
- Patel N. H. Developmental evolution: insights from studies of insect segmentation. Science. 1994 Oct 28;266(5185):581–590. doi: 10.1126/science.7939712. [DOI] [PubMed] [Google Scholar]
- Pirrotta V. Chromatin complexes regulating gene expression in Drosophila. Curr Opin Genet Dev. 1995 Aug;5(4):466–472. doi: 10.1016/0959-437x(95)90050-q. [DOI] [PubMed] [Google Scholar]
- Qian S., Capovilla M., Pirrotta V. Molecular mechanisms of pattern formation by the BRE enhancer of the Ubx gene. EMBO J. 1993 Oct;12(10):3865–3877. doi: 10.1002/j.1460-2075.1993.tb06065.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rost B. TOPITS: threading one-dimensional predictions into three-dimensional structures. Proc Int Conf Intell Syst Mol Biol. 1995;3:314–321. [PubMed] [Google Scholar]
- Sathe S. S., Harte P. J. The Drosophila extra sex combs protein contains WD motifs essential for its function as a repressor of homeotic genes. Mech Dev. 1995 Jul;52(1):77–87. doi: 10.1016/0925-4773(95)00392-e. [DOI] [PubMed] [Google Scholar]
- Shenkin P. S., Yarmush D. L., Fine R. M., Wang H. J., Levinthal C. Predicting antibody hypervariable loop conformation. I. Ensembles of random conformations for ringlike structures. Biopolymers. 1987 Dec;26(12):2053–2085. doi: 10.1002/bip.360261207. [DOI] [PubMed] [Google Scholar]
- Shimell M. J., Simon J., Bender W., O'Connor M. B. Enhancer point mutation results in a homeotic transformation in Drosophila. Science. 1994 May 13;264(5161):968–971. doi: 10.1126/science.7909957. [DOI] [PubMed] [Google Scholar]
- Shumacher A., Faust C., Magnuson T. Positional cloning of a global regulator of anterior-posterior patterning in mice. Nature. 1996 Sep 19;383(6597):250–253. doi: 10.1038/383250a0. [DOI] [PubMed] [Google Scholar]
- Simon J., Bornemann D., Lunde K., Schwartz C. The extra sex combs product contains WD40 repeats and its time of action implies a role distinct from other Polycomb group products. Mech Dev. 1995 Oct;53(2):197–208. doi: 10.1016/0925-4773(95)00434-3. [DOI] [PubMed] [Google Scholar]
- Simon J., Chiang A., Bender W. Ten different Polycomb group genes are required for spatial control of the abdA and AbdB homeotic products. Development. 1992 Feb;114(2):493–505. doi: 10.1242/dev.114.2.493. [DOI] [PubMed] [Google Scholar]
- Simon J. Locking in stable states of gene expression: transcriptional control during Drosophila development. Curr Opin Cell Biol. 1995 Jun;7(3):376–385. doi: 10.1016/0955-0674(95)80093-x. [DOI] [PubMed] [Google Scholar]
- Smith C., Giordano H., DeLotto R. Mutational analysis of the Drosophila snake protease: an essential role for domains within the proenzyme polypeptide chain. Genetics. 1994 Apr;136(4):1355–1365. doi: 10.1093/genetics/136.4.1355. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sondek J., Bohm A., Lambright D. G., Hamm H. E., Sigler P. B. Crystal structure of a G-protein beta gamma dimer at 2.1A resolution. Nature. 1996 Jan 25;379(6563):369–374. doi: 10.1038/379369a0. [DOI] [PubMed] [Google Scholar]
- Struhl G. A gene product required for correct initiation of segmental determination in Drosophila. Nature. 1981 Sep 3;293(5827):36–41. doi: 10.1038/293036a0. [DOI] [PubMed] [Google Scholar]
- Struhl G., Akam M. Altered distributions of Ultrabithorax transcripts in extra sex combs mutant embryos of Drosophila. EMBO J. 1985 Dec 1;4(12):3259–3264. doi: 10.1002/j.1460-2075.1985.tb04075.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Struhl G., Brower D. Early role of the esc+ gene product in the determination of segments in Drosophila. Cell. 1982 Nov;31(1):285–292. doi: 10.1016/0092-8674(82)90428-7. [DOI] [PubMed] [Google Scholar]
- Taunton J., Hassig C. A., Schreiber S. L. A mammalian histone deacetylase related to the yeast transcriptional regulator Rpd3p. Science. 1996 Apr 19;272(5260):408–411. doi: 10.1126/science.272.5260.408. [DOI] [PubMed] [Google Scholar]
- Wall M. A., Coleman D. E., Lee E., Iñiguez-Lluhi J. A., Posner B. A., Gilman A. G., Sprang S. R. The structure of the G protein heterotrimer Gi alpha 1 beta 1 gamma 2. Cell. 1995 Dec 15;83(6):1047–1058. doi: 10.1016/0092-8674(95)90220-1. [DOI] [PubMed] [Google Scholar]
- Warren R. W., Nagy L., Selegue J., Gates J., Carroll S. Evolution of homeotic gene regulation and function in flies and butterflies. Nature. 1994 Dec 1;372(6505):458–461. doi: 10.1038/372458a0. [DOI] [PubMed] [Google Scholar]
- Warren R., Carroll S. Homeotic genes and diversification of the insect body plan. Curr Opin Genet Dev. 1995 Aug;5(4):459–465. doi: 10.1016/0959-437x(95)90049-m. [DOI] [PubMed] [Google Scholar]
- White R. A., Wilcox M. Distribution of Ultrabithorax proteins in Drosophila. EMBO J. 1985 Aug;4(8):2035–2043. doi: 10.1002/j.1460-2075.1985.tb03889.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Whiteway M., Clark K. L., Leberer E., Dignard D., Thomas D. Y. Genetic identification of residues involved in association of alpha and beta G-protein subunits. Mol Cell Biol. 1994 May;14(5):3223–3229. doi: 10.1128/mcb.14.5.3223. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Williams F. E., Trumbly R. J. Characterization of TUP1, a mediator of glucose repression in Saccharomyces cerevisiae. Mol Cell Biol. 1990 Dec;10(12):6500–6511. doi: 10.1128/mcb.10.12.6500. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang C. C., Bienz M. Segmental determination in Drosophila conferred by hunchback (hb), a repressor of the homeotic gene Ultrabithorax (Ubx). Proc Natl Acad Sci U S A. 1992 Aug 15;89(16):7511–7515. doi: 10.1073/pnas.89.16.7511. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van der Lugt N. M., Alkema M., Berns A., Deschamps J. The Polycomb-group homolog Bmi-1 is a regulator of murine Hox gene expression. Mech Dev. 1996 Aug;58(1-2):153–164. doi: 10.1016/s0925-4773(96)00570-9. [DOI] [PubMed] [Google Scholar]