aa motif / Coiled-coils

3.6 a.a / turn in helix 

abcdefg 'a' &'d’ are hydrophobic residues 'e' and 'g' are found to be charged amino 

7.2 a.a / 2 turns acids 

 —7 amino acids per 2 turns in the helix 

For every turn there could be one hydrophobic residue coming same side of the helix 

Ex: GCN4

TLS Online TPP Program

#Id: 7904

#Unit 2. Cellular Organization

TLS Online TPP Program

#Id: 7905

#Unit 2. Cellular Organization

Mitophagy provides Mitochondrial Quality Control

TLS Online TPP Program

#Id: 7906

#Unit 2. Cellular Organization

When the environment of a cell has inadequate oxygen, enzymatic modification of proteins on the outer mitochondrial membrane induces mitophagy.

TLS Online TPP Program

#Id: 7907

#Unit 2. Cellular Organization

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

#Unit 2. Cellular Organization

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

#Unit 2. Cellular Organization

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.