CAMs fall into one of four major families: 

Cadherins

Immunoglobulin (Ig) superfamily

Integrins

Selectins

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Mitochondrial protein import requires: 

Tom proteins (Tom 20/22/70)

General import pore (Tom40)

Tim proteins (Tim23/17)

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Matrix-targeting sequences

Located at the N-terminus

Usually 20–50 amino acids in length

Rich in hydrophobic amino acids, positively charged basic amino acids (arginine & lysine), and hydroxylated ones (serine and threonine)

Amphipathicity of matrix-targeting sequences is critical to their function

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Matrix-targeting sequences

sequences for localizing proteins to mitochondria

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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.

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#Id: 7911

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

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Mitochondria-associated membranes (MAMs)

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