H. Rottensteiner et al., PIP2P - A TRANSCRIPTIONAL REGULATOR OF PEROXISOME PROLIFERATION IN THE YEAST SACCHAROMYCES-CEREVISIAE, EMBO journal, 15(12), 1996, pp. 2924-2934
In Saccharomyces cerevisiae, peroxisomes are the exclusive site for th
e degradation of fatty acids, Upon growth with the fatty acid oleic ac
id as sole carbon source, not only are the enzymes of beta-oxidation a
nd catalase A induced, but also the peroxisomal compartment as a whole
increases in volume and the number of organelles per cell rises, We p
reviously identified a cis-acting DNA sequence [oleate response elemen
t (ORE)] involved in induction of genes encoding peroxisomal proteins,
The aim of our investigation was to test whether a single mechanism a
cting via the ORE coordinates the events necessary for the proliferati
on of an entire organelle, Here we report the cloning and characteriza
tion of the oleate-specific transcriptional activator protein Pip2p (p
ip: peroxisome induction pathway), Pip2p contains a typical Zn(2)-Cys(
6) cluster domain and binds to OREs, A pip2 deletion strain is impaire
d in growth on oleate as sole carbon source and the induction of beta-
oxidation enzymes is abolished, Moreover, only a few, small peroxisome
s per cell can be detected. These results indicate that fatty acids ac
tivate Pip2p, which in turn activates the transcription of genes encod
ing beta-oxidation components and acts as the crucial activator of per
oxisomes.