RRC ID 36286
Author Tatomer DC, Rizzardi LF, Curry KP, Witkowski AM, Marzluff WF, Duronio RJ.
Title Drosophila Symplekin localizes dynamically to the histone locus body and tricellular junctions.
Journal Nucleus
Abstract The scaffolding protein Symplekin is part of multiple complexes involved in generating and modifying the 3' end of mRNAs, including cleavage-polyadenylation, histone pre-mRNA processing and cytoplasmic polyadenylation. To study these functions in vivo, we examined the localization of Symplekin during development and generated mutations of the Drosophila Symplekin gene. Mutations in Symplekin that reduce Symplekin protein levels alter the efficiency of both poly A(+) and histone mRNA 3' end formation resulting in lethality or sterility. Histone mRNA synthesis takes place at the histone locus body (HLB) and requires a complex composed of Symplekin and several polyadenylation factors that associates with the U7 snRNP. Symplekin is present in the HLB in the early embryo when Cyclin E/Cdk2 is active and histone genes are expressed and is absent from the HLB in cells that have exited the cell cycle. During oogenesis, Symplekin is preferentially localized to HLBs during S-phase in endoreduplicating follicle cells when histone mRNA is synthesized. After the completion of endoreplication, Symplekin accumulates in the cytoplasm, in addition to the nucleoplasm, and localizes to tricellular junctions of the follicle cell epithelium. This localization depends on the RNA binding protein ypsilon schachtel. CPSF-73 and a number of mRNAs are localized at this same site, suggesting that Symplekin participates in cytoplasmic polyadenylation at tricellular junctions.
Volume 5(6)
Pages 613-25
Published 2015-1-6
DOI 10.4161/19491034.2014.990860
PMID 25493544
PMC PMC4615279
MeSH Animals Cytoplasm / genetics Drosophila Drosophila Proteins / biosynthesis* Drosophila Proteins / genetics Embryo, Nonmammalian Embryonic Development* Gene Expression Regulation, Developmental Histones / genetics* Histones / metabolism Intranuclear Inclusion Bodies / genetics Intranuclear Inclusion Bodies / metabolism Mutation Nucleoplasmins / genetics Polyadenylation / genetics* Ribonucleoprotein, U7 Small Nuclear / genetics S Phase / genetics mRNA Cleavage and Polyadenylation Factors / biosynthesis* mRNA Cleavage and Polyadenylation Factors / genetics
IF 2.792
Times Cited 9
Drosophila DGRC#104292