Peroxisome reintroduction in Hansenula polymorpha requires Pex25 and Rho1

Vol. 193 No. 5, May 30, 2011. Pages 885–900.

The editors of The Journal of Cell Biology have been notified by Dr. Ida J. van der Klei that she and the other authors of the paper referenced above retract the paper. As a result of this retraction, no data in this paper should be cited in the scientific literature.

The authors provided the following statement:

Figs. 4 D and 5 C

The experiment shown in Fig. 4 D presents fluorescence microscopy analysis of a Hansenula polymorpha pex3 pex25 strain that produces Pex3-GFP under control of the inducible amine oxidase promoter (pex3 pex25 P_AMO PEX3-GFP). The results indicate that peroxisomes are not formed upon induction of Pex3-GFP synthesis. In this strain, indeed, PEX25 is deleted and P_AMO PEX3-GFP is properly introduced. However, it appeared that P_AMO PEX3-GFP was introduced in a pex11 pex25 strain (also used in this project), instead of a pex3 pex25 strain, explaining why peroxisomes were not formed.

For the experiment shown in Fig. 5 C, a pex3 pex25 P_AOX BIP _N30 PEX3-mCherry strain was constructed. The P_AOX BIP _N30 PEX3-mCherry construct was introduced in the same, wrong, stock of pex3 pex25 competent cells (used for the strain of Fig. 4 D), which were pex11 pex25 cells. This mistake explains why induction of BIP_N30Pex3-mCherry synthesis did not lead to peroxisome formation.

We have constructed a new pex3 pex25 P_AMO PEX3-GFP strain and repeated the experiment of Fig. 4 D. The outcome of the experiment was that peroxisomes were formed upon induction of Pex3-GFP synthesis (like in the control strain shown in Fig. 4 A).

Fig. 6, D–F

In the fluorescence microscopy images shown in Fig. 6 (D–F), P_AOXPEX11-mCherry was introduced in pex11 pex25 cells. Induction of Pex11-mCherry synthesis did not result in peroxisome formation. The strain used was indeed a pex11 pex25 double deletion strain. However, the mCherry fusion protein that was introduced appeared not to be correct. We made a new strain and repeated the experiment of Fig. 6 F. This experiment revealed that upon induction of Pex11-mCherry synthesis peroxisomes were formed. Hence, the conclusion that Pex25 is required for the formation of peroxisomes in H. polymorpha pex11 pex25 cells is not correct.

The authors apologize for any confusion these errors may have caused to the research community.