Supplementary MaterialsS1 Fig: Verification from the mutant recovery by RT-PCR particular to endogenous transcripts. antibody was utilized to look for the influence on CycE levels. Even in the absence of heat shock, the overall level and the number of cells with an intense CycE staining are reduced in the presence of heat shock Gal4 driver due to the leakiness of the driver. Scale bar represents 100 m.(TIF) pgen.1007204.s003.tif (1.4M) GUID:?FBA1C84E-2868-425B-BA12-0019239AC971 S4 Fig: Eye discs of mutants do not have ectopic cell death. (A) Control eye discs and eye discs overexpressing dE2F1a (GMRG4 dE2F1a) and dE2F1b (GMRG4 dE2F1b) are shown. Apoptotic cells and S-phase cells are visualized by a cell death marker, Cleaved Caspase-1 (Dcp-1, green) and EdU (red) respectively. The asterisks show apoptotic cells and arrow head show S-phase cells that are induced by overexpression of dE2F1a or dE2F1b. (B) Eye discs of control and mutants are immunostained for a neuronal marker (ELAV, blue) and a cell death marker, Cleaved Drosophila Caspase-1 (Dcp-1, green). (TIF) pgen.1007204.s004.tif (3.5M) GUID:?840B8547-8921-47B9-AA1B-0BC09CF3B6B9 S5 Fig: Overexpression of dE2F1a Prostaglandin E1 pontent inhibitor and dE2F1b in the eye. (A) Immunoblot (upper panel) and immunostaining (lower panel) with anti-Myc compare the expression levels of dE2F1a and dE2F1b. 20 pairs of the discs for each genotype were used for the Immunoblot and -tubulin is used as a loading control. The GMR-Gal4 driver is used to express Myc-tagged dE2F1a or dE2F1b in the eye.(TIF) pgen.1007204.s005.tif (1.6M) GUID:?36B142F6-3BFC-4B5F-B9DB-749C51500F0C S6 Fig: Multiple sequence alignment of the Marked Box (MB) domain of fruit flies and human. The MB domain sequences from the two dE2F1 isoforms, dE2F1a and dE2F1b, and all six canonical E2Fs from human, E2F1 Prostaglandin E1 pontent inhibitor to 6, are aligned. Highlighted in green are four amino acids that are identified to be important for specific interactions between E2F and RB family proteins (18). Red letters indicate the amino acid sequences coded by the E2F family has been viewed as a streamlined RB/E2F network, consisting of one activator (dE2F1) and one repressor (dE2F2). Here, we report that an uncharacterized isoform of dE2F1, hereon called dE2F1b, plays an important function during development and is functionally distinct from the widely-studied dE2F1 isoform, dE2F1a. dE2F1b contains an additional exon that inserts Prostaglandin E1 pontent inhibitor 16 amino acids to the evolutionarily conserved Marked Box domain. Analysis of RB/E2F network. Author summary The E2F1 (dE2F1) protein has been studied as one of the principal regulators of cell cycle control in both mitotic cells and cells undergoing a variant cell cycle called the endocycle. dE2F1 is the sole activator E2F of the highly streamlined RB/E2F network. However, there has been evidence suggesting that this simplistic view of the activator E2F may not be true and that dE2F1 can also provide a repressive function. Elucidating the dual role of dE2F1 in transcriptional regulation has been elusive. In our report, we investigate an uncharacterized isoform of dE2F1 that we have termed as dE2F1b. Notably, the evolutionarily conserved Marked Prostaglandin E1 pontent inhibitor Box domain, which is important for target specificity and protein-protein interactions, is altered in this isoform. Our findings suggest that dE2F1b is required for proper cell cycle control in both mitotic and endocycling cells. Strikingly, we show that dE2F1b has repressive functions in a context-dependent manner. Overall, MYH10 our findings reveal an unanticipated complexity to dE2F1, providing important insights into the dual function of dE2F1 in transcriptional regulation. Introduction The E2F family of transcription factors was first cloned as a cellular factor that binds to the Early E2 region of the adenovirus genome [1]. Since its discovery, families of E2F transcription factors have been identified in metazoans ranging.