Figure 4
From: Human Mitochondrial DNA-Protein Complexes Attach to a Cholesterol-Rich Membrane Structure
Nucleoid components are detected in purified MAM.
Sub-cellular fractionations of HEK293 cells were done according to29 Western-blot analyses using different markers to identify cytosolic (actin), ER (CALNX), mitochondrial (coxI, coxII, Twinkle, TFAM, cyclophilin D, ATAD3) and MAM (FACL4) components showed that in HEK293 cells, mitochondria cannot be easily separated from ER membranes. However, some MAM can be freed from mitochondrial membranes as evidenced by the absence of the mitochondrial membrane markers coxI and coxII. Mitochondrial nucleoid components are still detected in this otherwise mitochondria-free MAM-preparation (a). The amount of cholesterol (molar percentage of total lipids) in MAM is higher than in purified mitochondria derived from HEK293 cells (mt N =3 ; MAM N = 3) (b). ER, endoplasmic reticulum; MT, mitochondria; MAM, mitochondria associated membranes; FACL4, long-chain acyl-CoA synthetase 4; CALNX, calnexin; coxI cytochrome oxidase subunit I; coxII, cytochrome oxidase subunit II; CyP-d, Cyclophilin D; TFAM, mitochondrial transcription factor A.
