Mitochondrial carrier homolog 2: a clue to cracking the BCL-2 family riddle?

Atan Gross1

  • 1Department of Biological Regulation, Weizmann Institute of Science, Rehovot, 76100, Israel. atan.gross@weizmann.ac.il

Insights

The BCL-2 family regulates apoptosis at mitochondria. This review explores how a newly identified protein, Mtch2, interacts with BID to potentially control the mitochondrial apoptotic program.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • The BCL-2 family of proteins are key regulators of apoptosis.
  • Mitochondria play a central role in the apoptotic process, executing a 'mitochondrial apoptotic program'.
  • The precise mechanisms by which BCL-2 family members control this program are not fully understood.

Purpose of the Study:

  • To review current knowledge on BCL-2 family members and the mitochondrial apoptotic program.
  • To examine the potential role of a novel protein, mitochondrial carrier homolog 2 (Mtch2), in this process.

Main Methods:

  • Literature review of BCL-2 family functions in apoptosis.
  • Analysis of existing research on mitochondrial apoptotic pathways.
  • Examination of recent findings on the interaction between tBID and Mtch2.

Main Results:

  • BCL-2 family proteins are critical for initiating and regulating mitochondrial apoptosis.
  • The truncated form of BID (tBID) interacts with the uncharacterized protein Mtch2 in apoptotic cells.
  • Mtch2 shares similarities with mitochondrial carrier proteins (MCPs).

Conclusions:

  • Mtch2 is a novel protein identified as a potential player in the mitochondrial apoptotic program.
  • Further research is needed to elucidate the exact mechanism of Mtch2's involvement in apoptosis regulation.
  • Understanding Mtch2's role could offer new insights into controlling programmed cell death.

Related Concept Videos

Protein Transport into the Inner Mitochondrial Membrane01:34

Protein Transport into the Inner Mitochondrial Membrane

Nuclear encoded mitochondrial precursors are imported to the inner membrane in a multistep process involving two separate translocons, TIM22 and TIM23. TIM23 is a cation-selective pore that remains closed by the N terminal segment of the protein. Negative charges on the TIM23 act as a receptor for the incoming precursor, pulling the positively charged matrix-targeting sequence for peptide insertion and translocation.
Transport of mitochondrial precursors across the TIM23 channel is driven by...
Mitochondrial Protein Sorting01:39

Mitochondrial Protein Sorting

Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death.  Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
The ADP/ATP Carrier Protein01:42

The ADP/ATP Carrier Protein

ADP/ATP carrier or AAC protein is the most abundant carrier protein in the inner mitochondrial membrane. It transports large quantities of ADP and ATP, equivalent to the average human body weight, every day. Among other transporters, ACC protein is one of the best-studied members of the mitochondrial carrier protein family. The ADP/ATP carrier protein comprises two transmembrane helices connected to a loop and a single alpha-helix on the matrix side. It switches between two conformational...
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Mitochondrial Precursor Proteins01:39

Mitochondrial Precursor Proteins

Mitochondrial precursors are partially unfolded or loosely folded polypeptide chains. Newly synthesized precursors are inhibited from spontaneously folding into their native conformation by the cytosolic chaperones, heat shock proteins 70 (Hsp70), and mitochondrial import stimulation factors (MSFs). Precursors bound to MSFs are guided to the TOM70-TOM37 receptors, while precursors bound to Hsp70  chaperones are targetted to TOM20-TOM22 receptor complexes.
Most of the mitochondrial precursors...
Electron Transport Chain: Complex I and II01:46

Electron Transport Chain: Complex I and II

The mitochondrial electron transport chain (ETC) is the main energy generation system in the eukaryotic cells. However, mitochondria also produce cytotoxic reactive oxygen species (ROS) due to the large electron flow during oxidative phosphorylation. While Complex I is one of the primary sources of superoxide radicals, ROS production by Complex II is uncommon and may only be observed in cancer cells with mutated complexes.
ROS generation is regulated and maintained at moderate levels necessary...