Reference "Peroxisomes are involved in biotin biosynthesis in Aspergillus and Arabidopsis"

Reference ID

54985

Title

Peroxisomes are involved in biotin biosynthesis in Aspergillus and Arabidopsis

Source

J Biol Chem, 2011, vol. 286, pp. 30455-30461

Authors (7)

Tanabe-Y	Maruyama-J
Yamaoka-S	Yahagi-D
Matsuo-I	Tsutsumi-N
Kitamoto-K

Abstract

Among the eukaryotes only plants and a number of fungi are able to synthesize
biotin. Although initial events leading to the biosynthesis of biotin remain
largely unknown, the final steps are known to occur in the mitochondria. Here we
deleted the Aopex5 and Aopex7 genes encoding the receptors for peroxisomal
targeting signals PTS1 and PTS2, respectively, in the filamentous fungus
Aspergillus oryzae. In addition to exhibiting defects in the peroxisomal
targeting of either PTS1 or PTS2 proteins, the deletion strains also displayed
growth defects on minimal medium containing oleic acid as the sole carbon
source. Unexpectedly, these peroxisomal transport-deficient strains also
exhibited growth defects on minimal medium containing glucose as the sole carbon
source that were remediated by the addition of biotin and its precursors,
including 7-keto-8-aminopelargonic acid (KAPA). Genome database searches in
fungi and plants revealed that BioF protein/KAPA synthase, one of the biotin
biosynthetic enzymes, has a PTS1 sequence at the C terminus. Fungal DeltabioF
strains expressing the fungal and plant BioF proteins lacking PTS1 still
exhibited growth defects in the absence of biotin, indicating that peroxisomal
targeting of KAPA synthase is crucial for the biotin biosynthesis. Furthermore,
in the plant Arabidopsis thaliana, AtBioF localized to the peroxisomes through
recognition of its PTS1 sequence, suggesting involvement of peroxisomes in
biotin biosynthesis in plants. Taken together we demonstrate a novel role for
peroxisomes in biotin biosynthesis and suggest the presence of as yet
unidentified peroxisomal proteins that function in the earlier steps of biotin
biosynthesis.