Aldehyde dehydrogenase, Ald4p, is a major component of mitochondrial fluorescent inclusion bodies in the yeast Saccharomyces cerevisiae.
When Saccharomyces cerevisiae strain 3626 was cultured to the stationary phase in a medium that contained glucose, needle-like structures that emitted autofluorescence were observed in almost all cells by fluorescence microscopy under UV excitation. The needle-like structures completely overlapped with the profile of straight elongated mitochondria. Therefore, these structures were designated as mitochondrial fluorescent inclusion bodies (MFIBs). The MFIB-enriched mitochondrial fractions were successfully isolated and 2D-gel electrophoresis revealed that a protein of 54 kDa was only highly concentrated in the fractions. Determination of the N-terminal amino acid sequence of the 54-kDa protein identified it as a mitochondrial aldehyde dehydrogenase, Ald4p. Immunofluorescence microscopy showed that anti-Ald4p antibody specifically stained MFIBs. Freeze-substitution electron microscopy demonstrated that cells that retained MFIBs had electron-dense filamentous structures with a diameter of 10 nm in straight elongated mitochondria. Immunoelectron microscopy showed that Ald4p was localized to the electron-dense filamentous structures in mitochondria. These results together showed that a major component of MFIBs is Ald4p. In addition, we demonstrate that MFIBs are common features that appear in mitochondria of many species of yeast.
Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan.
Yoshiko
Y
Misonou
Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan.
Maiko
M
Kikuchi
Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan Present address: Division of Cell Biology, Institute of Life Science, Kurume University, Hyakunen-kohen 1-1, Kurume, Fukuoka 839-0864, Japan.
Hiroshi
H
Sato
Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan.
Tomomi
T
Inai
Department of Life Science, College of Science, Rikkyo University, Tokyo 171-8501, Japan Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
Tsuneyoshi
T
Kuroiwa
Laboratory of Medical Mycology, Research Institute for Disease Mechanism and Control, Nagoya University School of Medicine, Nagoya 466-8550, Japan Present address: Department of Microbiology, Aichi Gakuin University School of Dentistry, Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan.
Kenji
K
Tanaka
Department of Biology, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan miyakawa@yamaguchi-u.ac.jp.
Isamu
I
Miyakawa
Ald4p; Aldehyde dehydrogenase; Inclusion body; Mitochondria; Yeast