RETINOBLASTOMA‑RELATED interactions with key factors of the RNA‑directed DNA methylation (RdDM) pathway and its influence on root development
02 de mayo de 2023
Les invitamos a leer el artículo: "RETINOBLASTOMA‑RELATED interactions with key factors of the RNA‑directed DNA methylation (RdDM) pathway and its influence on root development" del Dr. Luis Alfredo Cruz Ramírez, Investigador de Cinvestav UGA-Langebio, junto con el doctorando Jesús León Ruiz del Posgrado de Biotecnología de Plantas Cinvestav.
Autores: Jesús León‑Ruiz, Annie Espinal‑Centeno, Ikram Blilou, Ben Scheres, Mario Arteaga‑Vázquez, Alfredo Cruz‑Ramírez.
Felicitamos al estudiantado y profesorado que contribuyeron en esta investigación por su arduo trabajo.
Abstract: Transposable elements and other repetitive elements are silenced by the RNA-directed DNA methylation pathway (RdDM). In RdDM, POLIV-derived transcripts are converted into double-stranded RNA (dsRNA) by the activity of RDR2 and subsequently processed into 24 nucleotide short interfering RNAs (24-nt siRNAs) by DCL3. 24-nt siRNAs serve as guides to direct AGO4–siRNA complexes to chromatin-bound POLV-derived transcripts generated from the template/target DNA. The interaction between POLV, AGO4, DMS3, DRD1, RDM1 and DRM2 promotes DRM2-mediated de novo DNA methylation. The Arabidopsis Retinoblastoma protein homolog (RBR) is a master regulator of the cell cycle, stem cell maintenance, and development. We in silico predicted and explored experimentally the protein–protein interactions (PPIs) between RBR and members of the RdDM pathway. We found that the largest subunits of POLIV and POLV (NRPD1 and NRPE1), the shared second largest subunit of POLIV and POLV (NRPD/E2), RDR1, RDR2, DCL3, DRM2, and SUVR2 contain canonical and non-canonical RBR binding motifs and several of them are conserved since algae and bryophytes. We validated experimentally PPIs between Arabidopsis RBR and several of the RdDM pathway proteins. Moreover, seedlings from loss-of-function mutants in RdDM and RBR show similar phenotypes in the root apical meristem. We show that RdDM and SUVR2 targets are up-regulated in the 35S:AmiGO–RBR background.
Keywords: Epigenetics, de novo DNA methylation, Gene silencing, RBR, Root development, Viridiplantae.