Comments on: Yet another new trick: A new E1

By: Mystery Rays from Outer Space - Meddling with things mankind is not meant to understand. Also, pictures of my kids » An embarassment of riches: The new E1, yet again

Fri, 21 Sep 2007 13:58:43 +0000

[...] E1, yet again By iayork Yeah, so this is getting a little repetitious. The new E1 I noted back in June, and then again in August, has been reported one more [...]

By: Mystery Rays from Outer Space - Meddling with things mankind is not meant to understand. Also, pictures of my kids » Quick E1 update

Fri, 03 Aug 2007 15:46:22 +0000

[...] E1 update By iayork A few weeks ago, when I posted about the identification of a new E1 enzyme,1 suicyte drew my attention to another paper on the [...]

By: iayork

iayork — Sat, 30 Jun 2007 18:46:02 +0000

Thanks for the heads-up. I usually go through the “Papers in press” secton, but I missed the importance of this one.

In fact Groettrup’s paper makes the finding sound significantly less exciting for two reasons. They say in their abstract that “The UBE1L2 mRNA is most abundantly expressed in the testis”, which makes it sound more like the human version of the mouse Ube1y (which would be relatively boring). Groetrupp’s tissue expression figure is very different from Jin et al (compare the former, Fig. 4, with the Jin et al supplementary Fig 2; in the one case there is maybe 15X more in the testis, in the other “testis” is one of the lowest expressors … but Groetrupp’s group did their own measurements, while Jin et al used database information from http://symatlas.gnf.org/SymAtlas/ , so I have more faith in Groetrupp;s here. (On the other hand Jin et al did show widespread expression in several cultured cells directly; less relevant, but circumstantial.) Jin did note that UBa6/Ube1L2 is expressed at much lower levels than Ube1, and that may be what Groettrups’ group is showing. The real question is whether there’s enough in all or most tissues to have an effect, and to answer that we probably need to know what effect to look for.

As you say, Groettrup’s group also didn’t show the E2 specificity, which is a really important point.

Comparing the two papers, Jin et al makes the story sound much more exciting than Pelzer et al do, and it easy to see why the former is in Nature while the latter is in JBC. We’ll have to see if Harper’s group oversold the story, or if Groettrup’s missed important aspects.

By: Suicyte

Suicyte — Sat, 30 Jun 2007 17:11:43 +0000

This might be the first time this E1 has been published in Nature, but about the same story has been published 3 weeks ago in JBC by the group of Marcus Groettrup, see http://www.jbc.org/cgi/content/abstract/C700111200v1

I haven’t read both papers carefully enough to judge the relative merits, but what I like about the JBC paper is that they keep the original name UBE1L2 for the gene instead of inventing a new one. The gene by itself is known for a long time, also that it will work as an E1. What is new is that this E1 acts on ubiquitin instead of another UBL protein, as everybody had expected. After all, there are several ubiquitin-like modifiers out there that still lack an E1.
On the other hand, the E2 specificity is clearly a point in favour of the Harper-paper.