Doing the right thing: Authors retract protein paper after finding experimental errors
Here’s the notice for “Ubiquitin‐specific protease 4 is inhibited by its ubiquitin‐like domain,” by MP Luna‐Vargas, AC Faesen, WJ van Dijk, M Rape, A Fish, and TK Sixma:
The above article from EMBO reports, published online on 18 March 2011, has been retracted by agreement between the authors and the journal Chief Editor, Howy Jacobs.
The authors have decided to retract this paper because, upon further analysis, the lower Km for the USP4 catalytic domain, which is crucial for the conclusions of the study, could not be reproduced under the described conditions. Additionally, the authors realized that an error was made in the binding experiment, leading to the report of an erroneously high affinity for the Ubl domain and Ubl‐insert. Because of these problems, the main conclusion of this work is no longer valid and the authors regret any problems this may have caused. An institutional pre‐investigation came to the conclusion that there are no grounds to suspect intentional misconduct. The authors would like to emphasize that the USP4 crystal structure, the ubiquitin binding data and the kinetic analysis of the minimal catalytic domain D1D2 are not in question.
The paper has been cited 18 times, according to Thomson Scientific’s Web of Knowledge.
We hadn’t seen the term “pre-investigation” before. (It did remind us of Ivan’s TEDMED talk about pre-conditions, including one that we all have and that is universally fatal.) Corresponding author Titia Sixma tells us:
It’s standard procedure at NKI for any retraction to see if there is any reason to suspect issues with integrity. The committee analyzed our efforts at reproduction, the original data and computer files and interviewed the authors; if they had concluded there was any doubt about integrity a more in depth analysis would have followed.
In fact I was very grateful for this, because in the process a likely cause for the erroneous binding assay result was found, which relieved my own lingering doubts. The errors are very unfortunate and should not have happened, and I feel very badly about this. We felt it was important to do the retraction as the errors really invaldiate the main conclusion of the paper, even though a substantial part of the paper is still valid (as indicated in the retraction notice).
Kudos — another example of doing the right thing.