TY  - JOUR
A1  - Meyer, Britta
A1  - Wurm, Jan Philip
A1  - Kötter, Peter
A1  - Leisegang, Matthias
A1  - Schilling, Valeska
A1  - Buchhaupt, Markus
A1  - Held, Martin
A1  - Bahr, Ute
A1  - Karas, Michael
A1  - Heckel, Alexander
A1  - Bohnsack, Markus
A1  - Wöhnert, Jens
A1  - Entian, Karl-Dieter
T1  - The Bowen–Conradi syndrome protein Nep1 (Emg1) has a dual role in eukaryotic ribosome biogenesis, as an essential assembly factor and in the methylation of Psi1191 in yeast 18S rRNA
T2  - Nucleic acids research
N2  - The Nep1 (Emg1) SPOUT-class methyltransferase is an essential ribosome assembly factor and the human Bowen–Conradi syndrome (BCS) is caused by a specific Nep1D86G mutation. We recently showed in vitro that Methanocaldococcus jannaschii Nep1 is a sequence-specific pseudouridine-N1-methyltransferase. Here, we show that in yeast the in vivo target site for Nep1-catalyzed methylation is located within loop 35 of the 18S rRNA that contains the unique hypermodification of U1191 to 1-methyl-3-(3-amino-3-carboxypropyl)-pseudouri-dine (m1acp3Psi). Specific 14C-methionine labelling of 18S rRNA in yeast mutants showed that Nep1 is not required for acp-modification but suggested a function in Psi1191 methylation. ESI MS analysis of acp-modified Psi-nucleosides in a DeltaNep1-mutant showed that Nep1 catalyzes the Psi1191 methylation in vivo. Remarkably, the restored growth of a nep1-1ts mutant upon addition of S-adenosylmethionine was even observed after preventing U1191 methylation in a deltasnr35 mutant. This strongly suggests a dual Nep1 function, as Psi1191-methyltransferase and ribosome assembly factor. Interestingly, the Nep1 methyltransferase activity is not affected upon introduction of the BCS mutation. Instead, the mutated protein shows enhanced dimerization propensity and increased affinity for its RNA-target in vitro. Furthermore, the BCS mutation prevents nucleolar accumulation of Nep1, which could be the reason for reduced growth in yeast and the Bowen-Conradi syndrome.
Y1  - 2010
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/20237
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30-85038
SN  - 1362-4962
SN  - 0305-1048
N1  - © The Author(s) 2010. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.5/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
VL  - 39
IS  - 4
SP  - 1526
EP  - 1537
PB  - Oxford Univ. Press
CY  - Oxford
ER  -