Epigenetic engineering of ribosomal RNA genes enhances protein production.
Selection of mammalian high-producer cell lines remains a major challenge for the biopharmaceutical manufacturing industry. Ribosomal RNA (rRNA) genes encode the major component of the ribosome but many rRNA gene copies are not transcribed due to epigenetic silencing by the nucleolar remodelling complex (NoRC) [6], which may limit the cell's full production capacity. Here we show that the knockdown of TIP5, a subunit of NoRC, decreases the number of silent rRNA genes, upregulates rRNA transcription, enhances ribosome synthesis and increases production of recombinant proteins. However, general enhancement of rRNA transcription rate did not stimulate protein synthesis. Our data demonstrates that the number of transcriptionally competent rRNA genes limits efficient ribosome synthesis. Epigenetic engineering of ribosomal RNA genes offers new possibilities for improving biopharmaceutical manufacturing and provides novel insights into the complex regulatory network which governs the translation machinery in normal cellular processes as well as in pathological conditions like cancer.
Santoro
Raffaella
R
Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland. raffaella.santoro@bsse.ethz.ch
Lienemann
Philipp
P
Fussenegger
Martin
M
D016475:3T3 Cells; D000818:Animals; D016466:CHO Cells; D018899:CpG Islands; D006224:Cricetinae; D003412:Cricetulus; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D018628:Gene Dosage; D020868:Gene Silencing; D005818:Genetic Engineering; D051379:Mice; D014176:Protein Biosynthesis; D012335:RNA, Ribosomal / Q000235:genetics*; D015854:Up-Regulation
D012335:RNA, Ribosomal
Biol Chem. 1999 Sep;380(9):1127-31
10543452
Cancer Genet Cytogenet. 1999 Feb;109(1):34-9
9973957
Mol Cell. 2006 May 5;22(3):351-61
16678107
Genes Dev. 2003 Jul 15;17(14):1691-702
12865296
Cell Mol Life Sci. 2007 Jan;64(1):29-49
17171232
Biotechnol Prog. 2003 Jan-Feb;19(1):121-9
12573014
Nat Rev Cancer. 2003 Mar;3(3):179-92
12612653
Biotechnol Bioeng. 2003 Jan 5;81(1):1-12
12432575
Growth Factors. 2007 Aug;25(4):209-26
18092230
Mol Cell. 2001 Sep;8(3):719-25
11583633
Genetics. 1986 Aug;113(4):1009-19
3744025
Nat Rev Mol Cell Biol. 2005 Jan;6(1):69-78
15688068
Nucleic Acids Res. 2007;35(7):2191-8
17355984
Science. 2003 Nov 21;302(5649):1399-401
14631041
Nat Genet. 2002 Nov;32(3):393-6
12368916
Nat Biotechnol. 1999 Feb;17(2):176-80
10052355
J Cell Biol. 1985 Nov;101(5 Pt 1):1749-56
4055895
EMBO J. 2001 Sep 3;20(17):4892-900
11532953
Gene. 2002 Jan 9;282(1-2):19-31
11814674
Cell Mol Life Sci. 2005 Sep;62(18):2067-79
16041568
Nat Biotechnol. 1998 May;16(5):468-72
9592397
Cell. 1989 Jun 2;57(5):753-61
2720786
J Biol Chem. 2004 Feb 20;279(8):6783-93
14610093
Mol Cell Biol. 2005 Apr;25(7):2539-46
15767661
Mol Cell Biol. 2003 Mar;23(5):1558-68
12588976
Genes Dev. 2006 May 15;20(10):1207-14
16702398
Mol Cell. 2006 Mar 3;21(5):629-39
16507361
EMBO J. 2005 Jan 12;24(1):120-7
15577942
EMBO J. 2002 Sep 2;21(17):4632-40
12198165