Functional dissection of the Suppressor of UnderReplication protein of Drosophila melanogaster: identification of domains influencing chromosome binding and DNA replication

• Published in: Genetica Vol. 124; no. 2-3; pp. 187 - 200
• Main Authors: Kolesnikova, T D, Makunin, I V, Volkova, E I, Pirrotta, V, Belyaeva, E S, Zhimulev, I F
• Format: Journal Article
• Language: English
• Published: Netherlands Springer Nature B.V 01-07-2005
• Subjects: Animals; Animals, Genetically Modified; Base Sequence; Chromosomes; Chromosomes - metabolism; Deoxyribonucleic acid; DNA; DNA - genetics; DNA Replication; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Drosophila melanogaster; Drosophila melanogaster - genetics; Drosophila melanogaster - metabolism; Drosophila Proteins - chemistry; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Female; Genes, Insect; Heterochromatin - metabolism; Insects; Kinases; Male; Mutation; Protein Binding; Protein Structure, Tertiary; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Salivary Glands - metabolism
• ISSN: 0016-6707; 1573-6857
• DOI: 10.1007/s10709-005-1167-3

The Suppressor of UnderReplication (SuUR) gene controls the DNA underreplication in intercalary and pericentric heterochromatin of Drosophila melanogaster salivary gland polytene chromosomes. In the present work, we investigate the functional importance of different regions of the SUUR protein by expressing truncations of the protein in an UAS-GAL4 system. We find that SUUR has at least two separate chromosome-binding regions that are able to recognize intercalary and pericentric heterochromatin specifically. The C-terminal part controls DNA underreplication in intercalary heterochromatin and partially in pericentric heterochromatin regions. The C-terminal half of SUUR suppresses endoreplication when ectopically expressed in the salivary gland. Ectopic expression of the N-terminal fragments of SUUR depletes endogenous SUUR from polytene chromosomes, causes the SuUR- phenotype and induces specific swellings in heterochromatin.