Identification of Endos interacting proteins in Drosophila embryos by immunoprecipitation and LC-MS-MS/MS analysis

ABSTRACT: The transition from oocyte to embryo requires translation of maternally provided transcripts that in Drosophila is activated by Pan Gu kinase to release a rapid succession of 13 mitotic cycles. Mitotic entry is promoted by several protein kinases that include Greatwall/Mastl, whose endosulfine substrates antagonize Protein Phosphatase 2A (PP2A), facilitating mitotic Cdk1/Cyclin B kinase activity. Here we show that hyperactive greatwallScant can not only be suppressed by mutants in its Endos substrate, but also by mutants in Pan Gu kinase subunits. Conversely, mutants in me31B or trailer hitch (tral), which encode a complex that represses hundreds of maternal mRNAs, enhance greatwallScant. Me31B and Tral proteins, known substrates of Pan Gu kinase, copurify with Endos. This echoes findings that budding yeast Dhh1, orthologue of Me31B, associates with Igo1/2, orthologues of Endos and substrates of the Rim15 orthologue of Greatwall. endos-derived mutant embryos show reduced Me31B and elevated transcripts for the mitotic activators Cyclin B, Polo and Twine/Cdc25. Together, our findings demonstrate a previously unappreciated conservation of the Greatwall-endosulfine pathway in regulating translational repressors and its interactions with the Pan Gu kinase pathway to regulate translation and/or stability of maternal mRNAs upon egg activation.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Drosophila Melanogaster (fruit Fly)

TISSUE(S): Embryo

SUBMITTER: Hélène Rangone  

LAB HEAD: David Moore Glover

PROVIDER: PXD036613 | Pride | 2024-08-09

REPOSITORIES: Pride