title: A New Mutation, hap1-2, Reveals a C Terminal Domain Function in AtMago Protein and Its Biological Effects in Male Gametophyte Development in Arabidopsis thaliana.
abstract: The exon-exon junction complex (EJC) is a conserved eukaryotic multiprotein complex that examines the quality of and determines the availability of messenger RNAs (mRNAs) posttranscriptionally. Four proteins, MAGO, Y14, eIF4AIII and BTZ, function as core components of the EJC. The mechanisms of their interactions and the biological indications of these interactions are still poorly understood in plants. A new mutation, hap1-2. leads to premature pollen death and a reduced seed production in Arabidopsis. This mutation introduces a viable truncated transcript AtMagoΔC. This truncation abolishes the interaction between AtMago and AtY14 in vitro, but not the interaction between AtMago and AteIF4AIII. In addition to a strong nuclear presence of AtMago, both AtMago and AtMagoΔC exhibit processing-body (P-body) localization. This indicates that AtMagoΔC may replace AtMago in the EJC when aberrant transcripts are to be degraded. When introducing an NMD mutation, upf3-1, into the existing HAP1/hap1-2 mutant, plants showed a severely reduced fertility. However, the change of splicing pattern of a subset of SR protein transcripts is mostly correlated with the sr45-1 and upf3-1 mutations, not the hap1-2 mutation. These results imply that the C terminal domain (CTD) of AtMago is required for the AtMago-AtY14 heterodimerization during EJC assembly, UPF3-mediated NMD pathway and the AtMago-AtY14 heterodimerization work synergistically to regulate male gametophyte development in plants.
authors: Department of Biology, Saint Bonaventure University, Saint Bonaventure, New York, United States of America.
authors: Kevin
authors: K
authors: Cilano
authors: Biochemistry Program, Saint Bonaventure University, Saint Bonaventure, New York, United States of America.
authors: Zachary
authors: Z
authors: Mazanek
authors: Department of Biology, Saint Bonaventure University, Saint Bonaventure, New York, United States of America.
authors: Mahmuda
authors: M
authors: Khan
authors: Biochemistry Program, Saint Bonaventure University, Saint Bonaventure, New York, United States of America.
authors: Sarah
authors: S
authors: Metcalfe
authors: Department of Biology, Saint Bonaventure University, Saint Bonaventure, New York, United States of America.|Biochemistry Program, Saint Bonaventure University, Saint Bonaventure, New York, United States of America.
authors: Xiao-Ning
authors: XN
authors: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000378:metabolism; D019281:Dimerization; D005091:Exons; D017343:Genes, Plant; D055993:Germ Cells, Plant; D006801:Humans; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000502:physiology*; D030821:Plants, Genetically Modified; D011058:Pollen / Q000502:physiology*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012323:RNA Processing, Post-Transcriptional; D012326:RNA Splicing; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D012639:Seeds / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; D018076:DNA, Complementary; C569920:Mago protein, Arabidopsis; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins