Interview Date: October 2009
From the Special Topic of
According to our Special Topics analysis on autophagy
research over the past decade, the scientist whose work
ranks at #9 by total citations is Dr. Isei Tanida, with 33
papers cited a total of 2,195 times. In
Essential Science IndicatorsSM from
Reuters, Dr. Tanida's record includes 37 papers, the
majority of which are classified under Biology &
Biochemistry, cited a total of 2,389 times between January
1, 1999 and June 30, 2009.
Dr. Tanida is the Section Chief for the Laboratory of
Biomembranes in the Department of Biochemistry and Cell
Biology at the National Institute of Infectious Diseases in
In this interview, he
talks with ScienceWatch.com about his research
Would you tell us a bit about your
educational background and research experiences?
I majored in Biology at the University of Tokyo, where I received my
Bachelor of Science degree in 1987. I also did my graduate work at the
University of Tokyo, earning my Master of Science degree in Biology in
1989, and my Ph.D. in 1997.
My research career started in 1989 at the Tonen Corporation's Central
Research Laboratory, where I worked as a Researcher in the Biotechnology
Section until 1997. I then moved to the Juntendo University School of
Medicine, where I was Assistant Professor in the Department of Biochemistry
until October of 2006. From November of 2006 to the present, I have been
with the National Institute of Infectious Diseases, where I am the Section
Chief of the Laboratory of Biomembranes, in the Department of Biochemistry
and Cell Biology.
What first interested you in autophagy?
Autophagic body in the vacuole of yeast. When I visited
Prof. Ohsumi's lab in 1991, Dr. Takeshige had just found this
autophagic body, which was a novel structure. Thereafter, I was interested
in the molecular mechanism of autophagy.
One of your highly cited papers is the 1999
Molecular Biology of the Cell article, "Apg7p/Cvt2p: A novel
protein-activating enzyme essential for autophagy" (10: 1367-79,
May 1999). Would you talk a little bit about this paper, its findings,
and why it is so highly cited?
Atg conjugations essential for
This is my first paper regarding autophagy. Cooperating with Dr. Ohsumi's
lab, I was searching in the dark for the Atg7 protein and its mutant. One
day, Dr. Ohsumi informed us that
Dr. Mizushima (he is now a professor at Tokyo Medical and Dental
University) had found the Atg12-Atg5 conjugate, and that Atg7 is
genetically essential for the conjugation.
One reason it is so highly cited is that Atg7 is a key enzyme for the
formation of autophagosomes, and another is, from the standpoint of the
ubiquitylation reaction, Atg7 is a unique E1-like enzyme that has at least
Another of your highly cited papers is the
Autophagy article, "Lysosomal turnover, but not a cellular
level, of endogenous LC3 is a marker for autophagy" (1: 84-91,
July-September 2005). Could you tell our readers something about this
This paper focused on the lysosomal flux of LC3 during autophagy. Autophagy
has at least a three-step reaction: autophagosome-formation for engulfing
the cytosol, lysosome-autophagosome fusion, and lysosomal degradation of
intra-autophagosomal contents. When autophagosome-formation is activated,
LC3-II is increased, but simultaneously lysosomal degradation of LC3-II is
At that time, many researchers were excited about the finding of LC3-II as
a unique autophagosomal marker, but few people considered lysosomal
degradation of LC3-II. Therefore, there was a confusion of translation of
the amount of LC3 to autophagic activity. In this paper, we showed that
lysosomal degradation of LC3-II is non-negligibly high during autophagy.
How has our knowledge of autophagy changed over the
It has increased like the Big Bang. Ten years ago, few scientists knew
about autophagy. Upon first hearing the term, many scientists asked me
"What? Like phagosomes or like fuzzy logic?" One of the most amazing facts
is that "autophagy" was employed as a key reaction in a gourmet adventure
Manga "TO-RI-KO" of a famous Japanese weekly Manga magazine "SHONEN JUMP"
several months ago. This means that now, even junior students know the word
"autophagy" via this comic.
Where would you like to take your research on
autophagy in the next decade?
I will focus on the molecular mechanisms of autophagy, and autophagy on
What would you say the "take-home message" about
your work should be?
Don't forget the lysosomal degradation of LC3-II during
Isei Tanida, Ph.D.
Laboratory of Biomembranes
Department of Biochemistry and Cell Biology
National Institute of Infectious Diseases
KEYWORDS: AUTOPHAGY, YEAST, MOLECULAR MECHANISM, ATG7
PROTEIN, AUTOPHAGOSOMES, LYSOSOMAL FLUX, LC3, LYSOSOME-AUTOPHAGOSOME
FUSION, LYSOSOMAL DEGRADATION, INTRA-AUTOPHAGOSOMAL CONTENTS,