Posttranscriptional networks controlled by the hnRNP-like RNA-binding protein AtGRP7

CHRISTINE NOLTE; CLAUS WEINHOLDT; IVO GROSSE; TINO KÖSTER; ESTEFANIA MANCINI; KATJA MEYER; JULIETA L, MATEOS; STAIGER, DOROTHEE

Congreso; RNA Alternative Splicing 2016; 2016

<!-- /* Font Definitions */@font-face{font-family:Arial;panose-1:2 11 6 4 2 2 2 2 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:-536859905 -1073711037 9 0 511 0;}@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0cm;margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman";mso-ansi-language:DE;mso-fareast-language:DE;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:11.0pt;mso-ansi-font-size:11.0pt;mso-bidi-font-size:11.0pt;font-family:Calibri;mso-ascii-font-family:Calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Calibri;mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;mso-ansi-language:DE;}.MsoPapDefault{mso-style-type:export-only;margin-bottom:10.0pt;line-height:115%;}@page WordSection1{size:612.0pt 792.0pt;margin:72.0pt 90.0pt 72.0pt 90.0pt;mso-header-margin:36.0pt;mso-footer-margin:36.0pt;mso-paper-source:0;}div.WordSection1{page:WordSection1;}-->Theglycine-rich RRM-containing protein AtGRP7(Arabidopsis thaliana glycine-richRNA-binding protein 7) negatively autoregulates its circadian oscillations via bindingto its pre-mRNA followed by alternative splicing-Nonsense-mediated decay.To unravel posttranscriptionalnetworks controlled by AtGRP7globally, in vivo RNA binding substrates were identified by RNAimmunoprecipitation (RIP)-seq.  Severalhundred transcripts co-precipitated with AtGRP7::AtGRP7:GFPfusion protein upon precipitation with  GFP Trap beads but not upon mock precipitationwith RFP Trap beads.  To resolve theimpact of AtGRP7 on its candidate targets,transcriptome profiling of atgrp7loss-of-function mutants and AtGRP7overexpressors was performed. A suite of transcripts bound by AtGRP7 showed altered steady-stateabundance in response to altered AtGRP7level. Furthermore, we identified transcripts aberrantly spliced in response toaltered levels of AtGRP7. Among thoseare several direct targets, indicating that AtGRP7 regulates alternativesplicing by direct binding to some transcripts in vivo and influences alternativesplicing decisions of others indirectly. Currently, we are analyzing howposttranslational modifications regulate the impact of AtGRP7 on its downstream targets.