Searching across hundreds of databases

Our searching services are busy right now. Your search will reload in five seconds.

Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Genetic interactions of hypomorphic mutations in the m7G cap-binding pocket of yeast nuclear cap binding complex: an essential role for Cbc2 in meiosis via splicing of MER3 pre-mRNA.

RNA (New York, N.Y.) | Nov 17, 2012

Nuclear cap binding protein complex (CBC) is a heterodimer of a small subunit (Cbc2 in yeast) that binds the m(7)G cap and a large subunit (Sto1 in yeast) that interacts with karyopherins. In order to probe the role of cap recognition in yeast CBC function, we introduced alanine mutations (Y24A, F91A, D120A, D122A, R129A, and R133A) and N-terminal deletions (NΔ21 and NΔ42) in the cap-binding pocket of Cbc2. These lesions had no effect on vegetative growth, but they ameliorated the cold-sensitivity of tgs1Δ cells that lack trimethylguanosine caps (a phenotype attributed to ectopic association of CBC with the m(7)G cap of the normally TMG-capped U1 snRNA), thereby attesting to their impact on cap binding in vivo. Further studies of the Cbc2-Y24A variant revealed synthetic lethality or sickness with null mutations of proteins involved in early steps of spliceosome assembly (Nam8, Mud1, Swt21, Mud2, Ist3, and Brr1) and with otherwise benign mutations of Msl5, the essential branchpoint binding protein. Whereas the effects of weakening CBC-cap interactions are buffered by other actors in the splicing pathway during mitotic growth, the NΔ42 allele causes a severe impediment to yeast sporulation and meiosis. RNA analysis revealed a selective defect in the splicing of MER3 and SAE3 transcripts in cbc2-NΔ42 diploids during attempted sporulation. An intronless MER3 cDNA fully restored sporulation and spore viability in the cbc2-NΔ42 strain, signifying that MER3 splicing is a limiting transaction. These studies reveal a new level of splicing control during meiosis that is governed by nuclear CBC.

Pubmed ID: 23002122 RIS Download

Mesh terms: Amino Acid Motifs | Amino Acid Substitution | Base Sequence | Binding Sites | DNA Helicases | Epistasis, Genetic | Gene Knockout Techniques | Introns | Meiosis | Methyltransferases | Molecular Sequence Data | Mutagenesis, Site-Directed | Nuclear Cap-Binding Protein Complex | Nuclear Proteins | RNA Precursors | RNA Splicing | RNA Splicing Factors | RNA, Fungal | RNA, Messenger | RNA-Binding Proteins | Recombinases | Ribonucleoproteins | Saccharomyces cerevisiae | Saccharomyces cerevisiae Proteins | Splicing Factor U2AF | Spores, Fungal

Research resources used in this publication

None found

Research tools detected in this publication

None found

Data used in this publication

None found

Associated grants

  • Agency: NIGMS NIH HHS, Id: R01 GM050288
  • Agency: NIGMS NIH HHS, Id: R01 GM052470
  • Agency: NIGMS NIH HHS, Id: GM50288
  • Agency: NIGMS NIH HHS, Id: GM52470

BioGRID (Data, Interactions)

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.

We have not found any resources mentioned in this publication.