Hsp70 gene association with nuclear speckles is Hsp70 promoter specific.
Many mammalian genes localize near nuclear speckles, nuclear bodies enriched in ribonucleic acid-processing factors. In this paper, we dissect cis-elements required for nuclear speckle association of the heat shock protein 70 (Hsp70) locus. We show that speckle association is a general property of Hsp70 bacterial artificial chromosome transgenes, independent of the chromosome integration site, and can be recapitulated using a 2.8-kilobase HSPA1A gene fragment. Association of Hsp70 transgenes and their transcripts with nuclear speckles is transcription dependent, independent of the transcribed sequence identity, but dependent on the Hsp70 promoter sequence. Transgene speckle association does not correlate with the amount of transcript accumulation, with large transgene arrays driven by different promoters showing no speckle association, but smaller Hsp70 transgene arrays with lower transcript accumulation showing high speckle association. Moreover, despite similar levels of transcript accumulation, Hsp70 transgene speckle association is observed after heat shock but not cadmium treatment. We suggest that certain promoters may direct specific chromatin and/or transcript ribonucleoprotein modifications, leading to nuclear speckle association.
Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801, USA.
Yan
Y
Hu
Matt
M
Plutz
Andrew S
AS
Belmont
D000818:Animals; D016466:CHO Cells; D002104:Cadmium / Q000494:pharmacology; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure*; D006224:Cricetinae; D003412:Cricetulus; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D011401:Promoter Regions, Genetic; D012313:RNA / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation; D019076:Transgenes
D018840:HSP70 Heat-Shock Proteins; C490786:HSPA1A protein, human; D002104:Cadmium; D012313:RNA