Transcription of Satellite III non-coding RNAs is a general stress response in human cells.
In heat-shocked human cells, heat shock factor 1 activates transcription of tandem arrays of repetitive Satellite III (SatIII) DNA in pericentromeric heterochromatin. Satellite III RNAs remain associated with sites of transcription in nuclear stress bodies (nSBs). Here we use real-time RT-PCR to study the expression of these genomic regions. Transcription is highly asymmetrical and most of the transcripts contain the G-rich strand of the repeat. A low level of G-rich RNAs is detectable in unstressed cells and a 10(4)-fold induction occurs after heat shock. G-rich RNAs are induced by a wide range of stress treatments including heavy metals, UV-C, oxidative and hyper-osmotic stress. Differences exist among stressing agents both for the kinetics and the extent of induction (>100- to 80.000-fold). In all cases, G-rich transcripts are associated with nSBs. On the contrary, C-rich transcripts are almost undetectable in unstressed cells and modestly increase after stress. Production of SatIII RNAs after hyper-osmotic stress depends on the Tonicity Element Binding Protein indicating that activation of the arrays is triggered by different transcription factors. This is the first example of a non-coding RNA whose transcription is controlled by different transcription factors under different growth conditions.
Istituto di Genetica Molecolare-Consiglio Nazionale delle Ricerche Via Abbiategrasso 207, 27100 Pavia.
Rut
R
Valgardsdottir
Ilaria
I
Chiodi
Manuela
M
Giordano
Antonio
A
Rossi
Silvia
S
Bazzini
Claudia
C
Ghigna
Silvano
S
Riva
Giuseppe
G
Biamonti
D000818:Animals; D016466:CHO Cells; D022003:Cell Nucleus Structures / Q000737:chemistry / Q000648:ultrastructure; D006224:Cricetinae; D003412:Cricetulus; D004276:DNA, Satellite / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000378:metabolism; D006367:HeLa Cells; D000076249:Heat Shock Transcription Factors; D018869:Heat-Shock Response; D006801:Humans; D050778:NFATC Transcription Factors / Q000502:physiology; D009997:Osmotic Pressure; D022661:RNA, Untranslated / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation
D004276:DNA, Satellite; D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; D050778:NFATC Transcription Factors; D022661:RNA, Untranslated; D014157:Transcription Factors