NMD is essential for hematopoietic stem and progenitor cells and for eliminating by-products of programmed DNA rearrangements.
Nonsense-mediated mRNA decay (NMD) is a post-transcriptional surveillance process that eliminates mRNAs containing premature termination codons (PTCs). NMD has been hypothesized to impact on several aspects of cellular function; however, its importance in the context of a mammalian organism has not been addressed in detail. Here we use mouse genetics to demonstrate that hematopoietic-specific deletion of Upf2, a core NMD factor, led to the rapid, complete, and lasting cell-autonomous extinction of all hematopoietic stem and progenitor populations. In contrast, more differentiated cells were only mildly affected in Upf2-null mice, suggesting that NMD is mainly essential for proliferating cells. Furthermore, we show that UPF2 loss resulted in the accumulation of nonproductive rearrangement by-products from the Tcrb locus and that this, as opposed to the general loss of NMD, was particularly detrimental to developing T-cells. At the molecular level, gene expression analysis showed that Upf2 deletion led to a profound skewing toward up-regulated mRNAs, highly enriched in transcripts derived from processed pseudogenes, and that NMD impacts on regulated alternative splicing events. Collectively, our data demonstrate a unique requirement of NMD for organismal survival.
Weischenfeldt
Joachim
J
Section for Gene Therapy Research, Copenhagen University Hospital, 2100 Copenhagen, Denmark.
Damgaard
Inge
I
Bryder
David
D
Theilgaard-Mönch
Kim
K
Thoren
Lina A
LA
Nielsen
Finn Cilius
FC
Jacobsen
Sten Eirik W
SE
Nerlov
Claus
C
Porse
Bo Torben
BT
D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D002478:Cells, Cultured; D018389:Codon, Nonsense / Q000235:genetics / Q000502:physiology*; D020869:Gene Expression Profiling; D015321:Gene Rearrangement / Q000235:genetics / Q000502:physiology*; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D054503:Lymphoid Progenitor Cells / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008954:Models, Biological; D020411:Oligonucleotide Array Sequence Analysis; D020871:RNA Stability / Q000235:genetics*; D016601:RNA-Binding Proteins; D017384:Sequence Deletion / Q000502:physiology*
D002352:Carrier Proteins; D018389:Codon, Nonsense; D016601:RNA-Binding Proteins; C529977:Upf2 protein, mouse