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Spotted‐dick, a zinc‐finger protein of Drosophila required for expression of Orc4 and S phase
Author(s) -
Page Andrew R,
Kovacs Andras,
Deak Peter,
Tőrők Tibor,
Kiss Istvan,
Dario Paulo,
Bastos Cristina,
Batista Pedro,
Gomes Rui,
Ohkura Hiro,
Russell Steven,
Glover David M
Publication year - 2005
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600890
Subject(s) - biology , dna replication , endoreduplication , zinc finger , microbiology and biotechnology , mitosis , gene , chromatin , schneider 2 cells , zinc finger transcription factor , cell cycle , transcription factor , rna interference , genetics , rna
The highly condensed chromosomes and chromosome breaks in mitotic cells of a Drosophila mutant, spotted‐dick/pita , are the consequence of defects in DNA replication. Reduction of levels of Spotted‐dick protein, by either RNAi or mutation, leads to the accumulation of cells that have DNA content intermediate to 2N and 4N in proliferating tissues and also compromises endoreduplication in larval salivary glands. The Spotted‐dick Zinc‐finger protein is present in the nuclei of cells committed to proliferation but necessary in cells undertaking S phase. We show that Spotted‐dick/Pita functions as a transcription factor and that, in cultured S2 cells, it is an activator of expression of some 30 genes that include the Orc4 gene, required for initiation of DNA replication. Chromatin immunoprecipitation indicates that it associates with the genes that it activates in S2 cells together with other sites that could represent genes activated in other tissues. We discuss the role of Spotted‐dick in the coordination of cellular growth and DNA replication.