Autophagy is related with a diverse spectrum of diseases and has
long been anticipated as a therapeutic option from the point of view of
A group of
researchers, including Tomonori Kimura, a researcher at the Department
of Nephrology, Osaka University (the research was conducted at the
University of New Mexico, USA), identified the molecular machinery by
which autophagy mediates secretion of the inflammatory cytokine*2,
interleukin-1 beta, in corporation with SNARE proteins*3.
‘The newly-identified autophagy-dependent secretory system will open another dimension for therapeutic approaches through the secretory role of autophagy.’
In addition to interleukin-1 beta, leaderless proteins such as
ferritin, whose secretory system has not been identified, are also found
to be secreted based on the same autophagy machinery. Therefore, the
newly-identified autophagy-dependent secretory system facilitates the
secretion of leaderless proteins*4, and plays fundamental roles in this
Tomonori Kimura said, "Our findings will open another
dimension for therapeutic approaches through the secretory role of
Autophagy is a self-degradative process for cellular homeostasis.
Autophagosome sequesters the degradative targets, whose process is
followed by fusion with lysosomes for degradation of its contents.
Recently, autophagy is also reported to play a role in secretion.
2 Inflammatory cytokine
A subset of cytokines (proteins secreted from cells to mediate
information to other cells) which promotes inflammation. Interleukin-1
beta is a major inflammatory cytokine which is activated and released
3 SNARE proteins
SNARE proteins mediates vesicular fusion, such as fusion between
cellular plasma membrane and cytoplasmic vesicles. This fusion is
mediated by a set of SNARE proteins, generally consisting of Qa-, Qb-,
Qc-, and R-SNARE proteins.
4 Leaderless protein
Signal peptides are short peptides in proteins through which proteins
are bound for specific cellular distribution or secretion. A number of
proteins do not have signal peptides (called leaderless proteins), and
their secretory pathway have not been elucidated thus far.