TY - JOUR
T1 - Geminivirus Rep protein interferes with the plant DNA methylation machinery and suppresses transcriptional gene silencing
AU - Rodríguez-Negrete, Edgar
AU - Lozano-Durán, Rosa
AU - Piedra-Aguilera, Alvaro
AU - Cruzado, Lucia
AU - Bejarano, Eduardo R.
AU - Castillo, Araceli G.
PY - 2013/7
Y1 - 2013/7
N2 - Cytosine methylation is an epigenetic mark that promotes gene silencing and plays an important role in genome defence against transposons and invading DNA viruses. Previous data showed that the largest family of single-stranded DNA viruses, Geminiviridae, prevents methylation-mediated transcriptional gene silencing (TGS) by interfering with the proper functioning of the plant methylation cycle. Here, we describe a novel counter-defence strategy used by geminiviruses, which reduces the expression of the plant maintenance DNA methyltransferases, METHYLTRANSFERASE 1 (MET1) and CHROMOMETHYLASE 3 (CMT3), in both locally and systemically infected tissues. We demonstrated that the virus-mediated repression of these two maintenance DNA methyltransferases is widespread among geminivirus species. Additionally, we identified Rep (Replication associated protein) as the geminiviral protein responsible for the repression of MET1 and CMT3, and another viral protein, C4, as an ancillary player in MET1 down-regulation. The presence of Rep suppressed TGS of an Arabidopsis thaliana transgene and of host loci whose expression was strongly controlled by CG methylation. Bisulfite sequencing analyses showed that the expression of Rep caused a substantial reduction in the levels of DNA methylation at CG sites. Our findings suggest that Rep, the only viral protein essential for replication, displays TGS suppressor activity through a mechanism distinct from that thus far described for geminiviruses.
AB - Cytosine methylation is an epigenetic mark that promotes gene silencing and plays an important role in genome defence against transposons and invading DNA viruses. Previous data showed that the largest family of single-stranded DNA viruses, Geminiviridae, prevents methylation-mediated transcriptional gene silencing (TGS) by interfering with the proper functioning of the plant methylation cycle. Here, we describe a novel counter-defence strategy used by geminiviruses, which reduces the expression of the plant maintenance DNA methyltransferases, METHYLTRANSFERASE 1 (MET1) and CHROMOMETHYLASE 3 (CMT3), in both locally and systemically infected tissues. We demonstrated that the virus-mediated repression of these two maintenance DNA methyltransferases is widespread among geminivirus species. Additionally, we identified Rep (Replication associated protein) as the geminiviral protein responsible for the repression of MET1 and CMT3, and another viral protein, C4, as an ancillary player in MET1 down-regulation. The presence of Rep suppressed TGS of an Arabidopsis thaliana transgene and of host loci whose expression was strongly controlled by CG methylation. Bisulfite sequencing analyses showed that the expression of Rep caused a substantial reduction in the levels of DNA methylation at CG sites. Our findings suggest that Rep, the only viral protein essential for replication, displays TGS suppressor activity through a mechanism distinct from that thus far described for geminiviruses.
KW - C4
KW - CHROMOMETHYLASE3
KW - DNA methylation
KW - Geminivirus
KW - Gene silencing
KW - METHYLTRANSFERASE1
KW - Rep
KW - Transcriptional gene silencing suppressor
UR - http://www.scopus.com/inward/record.url?scp=84879622253&partnerID=8YFLogxK
U2 - 10.1111/nph.12286
DO - 10.1111/nph.12286
M3 - Artículo
SN - 0028-646X
VL - 199
SP - 464
EP - 475
JO - New Phytologist
JF - New Phytologist
IS - 2
ER -