Hh binds to Ptc, causing Ptc to be endocytosed from the cell surface and degraded, relieving the inhibition of Smo.

TLS Online TPP Program

#Id: 7907

#XL - Q Biochemistry

Parkinson’s disease is caused by mutations in two gene encoding proteins that can mediate mitophagy:

PINK1 (a kinase)

Parkin (E3 ubiquitin ligase)

TLS Online TPP Program

#Id: 7908

#XL - Q Biochemistry

In healthy mitochondria, PINK1 resides in the mitochondrial matrix.

In damaged or dysfunctional mitochondria, PINK1 resides on the outer mitochondrial membrane, where it recruits cytosolic Parkin.

TLS Online TPP Program

#Id: 7909

#XL - Q Biochemistry

Membrane contact sites (MCSs)

Mitochondria establish MCSs with many other organelles, including ER, lysosomes, peroxisomes, the plasma membrane, the Golgi, endosomes, and even lipid droplets.

TLS Online TPP Program

#Id: 7910

#XL - Q Biochemistry

Mitochondria-associated membranes (MAMs)

The portions of the ER membranes that form special contact regions with the mitochondria.

TLS Online TPP Program

#Id: 7911

#XL - Q Biochemistry

MCSs also serve as interfaces for the transfer of ions (Ca+2 ) and small molecules (glycerophospholipids) between the ER and mitochondria.

TLS Online TPP Program

#Id: 7912

#XL - Q Biochemistry

The majority of proteins located in mitochondria are not encoded by mtDNA, they are encoded by genes in the nucleus and are imported into the mitochondria after their synthesis in the cytosol.