Eukaryotic Transcription TERMINATION - CPSF & Integrator Pathway

[@theCrux]

If you are looking for details on the mechanism/process of CPSF/CStF assisted RNA cleavage during transcription termination, you can find it here: kzbin.info/www/bejne/Z2GXpnmFqamNhpI

[@Tim999-xl5kx]

it looks like you left out how you remove s5 from CTD tail which is important step in phosphorylation state of Serine in the tail of CTD domain. Thank you, you lecture provides great overview of the topic. I enjoyed it.

[@theCrux]

Excellent catch! I have been thinking of making a video on CTD regulation. I might soon :) Thanks for the input!

[@dXoverdteqprogress]

Brilliant, as per usual.

[@beinghimself]

This, with 3d videos to summarise steps in your head overall, is the best way to study genetics

[@sayakdhar5407]

glad you returned.

[@niteekachandel3621]

Amazing explanation

[@jsinovercos]

I remember at the end of the elongation video that directly precedes this one in the series, S5 on the CTD is also phosphorylated but it is not indicated in the termination mechanisms of this video. Is the CTD S5 still phosphorylated when termination happens? Or was it dephosphorylated at one point during elongation, and if so does that have functional significance?

[@theCrux]

S5 eventually gets de-phosphorylated (not all of it though, so just the levels drop) as the Polymerase complex moves into productive elongation... especially close to termination. The predominant enzyme involved in this is Ssu72 (sometimes Scp1). The understanding of regulation on this is a bit foggy.

[@jsinovercos]

@@theCrux Interesting...thanks for clarifying! And I forgot to say thank you so much for making these videos! I can't imagine how many papers I would have had to pour through to synthesize all this information on my own. You've saved this starting grad student a lot of time and frustration :)

[@theCrux]

@@jsinovercos There is a lot I would like to cover in these videos without it being overwhelming. The content is meant to be a digested overview, and I am happy to hear that it is useful. Also, if you are interested in learning more about CTD-mods of RNA Pol, see the review "The RNA Polymerase II Carboxy-Terminal Domain (CTD) Code" - especially Figure 7.

[@vjp286]

What's the role of hybrid in transcription..

[@dXoverdteqprogress]

Slightly unrelated question: does splicing happen after cleavage or does the process begin during elongation? The traditional view is that it happens after cleavage, but I have seen a paper which suggests it starts much earlier. Can you shed any light on this? Thanks! Keep up the good work.

[@theCrux]

Splicing in eukaryotic [sic, mammalian] "mRNAs" is typically co-transcriptional at the 5' end of the gene (although it makes sense from kinetics POV, it is not always the preferable or true for a given gene). At the 3' end, mostly it is post-transcriptional, because cells have less time to process the RNA while still in termination. That being said, it is not a rule that 5' to 3' end follows co-to-post transcriptional splicing association. Here is an extreme case of post-transcriptional splicing if you are interested: pubmed.ncbi.nlm.nih.gov/16096058/ I will be making a co/post-transcriptional modifications video to go over these sort of things :)

[@dXoverdteqprogress]

@@theCrux Thank you for the answer - and the paper. Looking forward to the next video. Cheers.

[@sapnasalaria3957]

👌✨