TY - JOUR
T1 - Depletion of the yeast nuclear exosome subunit Rrp6 results in accumulation of polyadenylated RNAs in a discrete domain within the nucleolus
AU - Carneiro, Tiago
AU - Carvalho, Celia
AU - Braga, Jose
AU - Rino, Jose
AU - Milligan, Laura
AU - Tollervey, David
AU - Carmo-Fonseca, Maria
PY - 2007/6
Y1 - 2007/6
N2 - Recent data reveal that a substantial fraction of transcripts generated by RNA polymerases I, II, and III are rapidly degraded in the nucleus by the combined action of the exosome and a noncanonical poly(A) polymer-ase activity. This work identifies a domain within the yeast nucleolus that is enriched in polyadenylated RNAs in the absence of the nuclear exosome RNase Rrp6 or th exosome cofactor Mtr4. In normal yeast cells, poly(A) (+) RNA was undetectable in the nucleolus but the depletion of either Rrp6 or Mtr4 led to the accumulation of polyadenylated RNAs in a discrete subnucleolar region. This nucleolar poly(A) domain is enriched for the U14 snoRNA and the snoRNP protein Nop1 but is distinct from the nucleolar body that functions in snoRNA maturation. In strains lacking both Rrp6 and the poly(A) polymerase Trf4, the accumulation of poly(A) (+) RNA was suppressed, suggesting the involvement of the Trf4-Air1/2-Mtr4 polyadenylation (TRAMP) complex. The accumulation of polyadenylated snoRNAs in a discrete nucleolar domain may promote their recognition as substrates for the exosome.
AB - Recent data reveal that a substantial fraction of transcripts generated by RNA polymerases I, II, and III are rapidly degraded in the nucleus by the combined action of the exosome and a noncanonical poly(A) polymer-ase activity. This work identifies a domain within the yeast nucleolus that is enriched in polyadenylated RNAs in the absence of the nuclear exosome RNase Rrp6 or th exosome cofactor Mtr4. In normal yeast cells, poly(A) (+) RNA was undetectable in the nucleolus but the depletion of either Rrp6 or Mtr4 led to the accumulation of polyadenylated RNAs in a discrete subnucleolar region. This nucleolar poly(A) domain is enriched for the U14 snoRNA and the snoRNP protein Nop1 but is distinct from the nucleolar body that functions in snoRNA maturation. In strains lacking both Rrp6 and the poly(A) polymerase Trf4, the accumulation of poly(A) (+) RNA was suppressed, suggesting the involvement of the Trf4-Air1/2-Mtr4 polyadenylation (TRAMP) complex. The accumulation of polyadenylated snoRNAs in a discrete nucleolar domain may promote their recognition as substrates for the exosome.
U2 - 10.1128/MCB.00120-07
DO - 10.1128/MCB.00120-07
M3 - Article
SN - 0270-7306
VL - 27
SP - 4157
EP - 4165
JO - Molecular and Cellular Biology
JF - Molecular and Cellular Biology
IS - 11
ER -