Basic structure and function of cells
9.e1
1
RETPaHC
The transcription factor EB (TFEB) is responsible for regulating lyso-
somal biogenesis and function, lysosome-to-nucleus signalling and
lipid catabolism (for further reading, see Settembre et al (2013)). If any
of the actions of lysosomal hydrolases, of the lysosome acidification
mechanism or of lysosomal membrane proteins fails, the degradation
and recycling of extracellular substrates delivered to lysosomes by the
late endosome and the degradation and recycling of intracellular sub-
strates by autophagy lead to progressive lysosomal dysfunction in
several tissues and organs.
Experimentally, TFEB activation can reduce the accumulation of
the pathogenic protein in a cellular model of Huntington’s disease (a
neurodegenerative genetic disorder that affects muscle coordination)
and improves the Parkinson’s disease phenotype in a murine model.
Cristae are abundant in mitochondria seen in cardiac muscle
cells and in steroid-producing cells (in the suprarenal cortex, corpus
luteum and Leydig cells). The protein steroidogenic acute regulatory
protein (StAR) regulates the synthesis of steroids by transporting