Differential stress induction of individual Alu loci: implications for transcription and retrotransposition.
While human Alu repeats can be considered to be members of an extremely large, globally regulated, multigene family, each member of this family resides within a different sequence context that might uniquely modulate its transcription. Unique 3' flanking sequences for several transcriptionally active human Alu elements were identified by cDNA cloning and used for primer extension analysis to compare the basal and stress-induced expression of the corresponding Alu loci. Each of six Alu loci investigated exhibits a unique pattern of expression in three different human cell lines and in response to stress induction. The sequence context surrounding each Alu member uniquely determines its transcriptional regulation. In many cases, the individual Alu loci and total Alu RNA exhibit opposing patterns of expression implying that local rather than global regulation ultimately determines the expression of individual members. Some of the stresses, which induce Alu transcription, increase co-expression of LINE1 RNA, another requirement for Alu retrotransposition.
Li
T H
TH
Section of Molecular and Cellular Biology, University of California, Davis, CA 95616-8535, USA.
Schmid
C W
CW
D020087:Alu Elements / Q000235:genetics*; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006367:HeLa Cells; D018869:Heat-Shock Response / Q000235:genetics; D006358:Hot Temperature; D006801:Humans; D020014:K562 Cells; D020084:Long Interspersed Nucleotide Elements / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D012313:RNA / Q000235:genetics / Q000378:metabolism; D018626:Retroelements / Q000235:genetics; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological / Q000503:physiopathology*; D013997:Time Factors; D014158:Transcription, Genetic
D018076:DNA, Complementary; D018626:Retroelements; D012313:RNA