I'm Simon Wilkinson from the University of Edinburgh and today,
I'm going to tell you all about structure, function and physiological role of
a classic molecule, known as cargo receptors, which
mediate a number of homeostatic processes,
collectively known as selective autophagy.
Macroautophagy or as I shall refer to it from here on in, autophagy,
is the major pathway for degradation of cytosolic multi-molecular complexes. Whereas
proteases such as site-specific proteases or
the proteasome tend to act upon single polypeptide molecules.
The autophagy pathway encapsulates organelles,
pathogens and large protein complexes in vesicles called
autophagosomes that are destined for degradation via fusion with lysosomes.
Autophagy thus serves several purposes.
The metabolites released from lysosomal degradation of the cargos of autophagy,
and we defined cargos here as the organelle,
pathogen or protein complexes encapsulated into the autophagosomes, and feed into
recycling into new structures via anabolic pathways or catabolism to produce energy.
However autophagy also, and this is the critical subject of today's lecture,
results in removal from the cytosolic milieu of the cell of these cargos.
In fact autophagy to feed metabolism tends to operate under
nutrient stress and in this instance cargos are sacrificed in a non-selective manner.
Effectively autophagy catabolises bulk cytosol in order to keep cells alive.
However we're interested today in selective autophagy.
This is where autophagic degradation specifically targets unwanted cargos in order to
remove them selectively from the cytosol
of cells and this is critical for cellular health.