Methylation in the + strand influence the expression of gene in the - strand?

[yao_licr]

Hi all,
I have a general question about how the methylation within the TSS 1000 bp will influence the expression of the gene?

It is easy to understand that if the methylation happens in the same strand as the gene sits, it will potentially repress the expression of the corresponding gene; but if the methylation (within TSS 1000 bp) happens in the + strand, so could it potentially repress the corresponding gene in the - strand as well? Is there any literature about that?

Thanks a lot!

Yao

[dpryan]

It's highly likely that methylation on the + strand can affect transcription on the - strand. I've never read a paper that showed that, but I've also never looked.

[volks]

most CpGs in the genome are either unmethylated or methylated on both strands (CG is a palindromic sequence). any hemi-methylated CpGs are quickly methylated on both strands by DNMT1 (that is what is happening for every cellular replication cycle). i am not aware of any finding that would answer your question more appropriately.

[hamarillo]

Bottom line is, how could enzymes distinguish which strand they are methylating?

when you perform a sequencing experiment and on the analysis you find that there is no equilibrium between the methylation at - and + strands; is it an indicator of an experimental artefact or a sequencer failure?