(Forwarded) Re: 5'UTR of eukaryotic mRNA

[Ed Rybicki]

Forwarded message:
From:     Self <MICRO/ED>
To:       blume_j at hanv01.dnet.sandoz.com (John E. Blume)
Subject:  Re: 5'UTR of eukaryotic mRNA
Reply-to: ed at micro.uct.ac.za
Date:     1 Sep 93 17:19:59

> > I have a simple question:
> > How long can be 5'UTR of eukaryotic mRNA? How many bases has the longest
> > one, which is known up to now?
>
> We are currently playing with a message that has an approx. 430 nt 5'UTR.
> The analogous gene in mice might have an even longer UTR (>600 nt) but I
> am not sure that I believe my data yet. The gene is glucokinase from rat
> beta-cells.

Anyone familiar with virus mRNA / genomic RNA will know of several with
LOOOONG 5'-UTRs: I can think of polio/picornaviruses, potyviruses offhand,
which have UTRs of 0.6 - 1.2 kb.  Cauliflower mosaic virus (a
pararetrovirus) also has long 5'-UTRs.

> I am wondering if nature would have made such an obvious structural
> nightmare for no reason - are there translational control games being
> played here?

And yes, it is ALL about translational control: the picorna - and
potyviral UTR is a translational enhancer, among other things.

  ____________________________________________________________________
 | Ed Rybicki, PhD             |       "Lord, won't you buy me        |
 | (ed at micro.uct.ac.za)        |                                      |
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