Mitochondrial inner membrane and matrix (MIM/MM)

The mitochondrial inner membrane (IMM) and matrix represent the innermost functional compartments of the mitochondria, serving as the central hub for cellular energy production. The IMM is highly folded into cristae and contains the protein complexes of the electron transport chain (Complexes I-IV) and ATP synthase, which are essential for oxidative phosphorylation [1]. The matrix is the fluid-filled space enclosed by the IMM, housing the enzymes for the tricarboxylic acid (TCA) cycle, mitochondrial DNA, and the machinery for fatty acid oxidation [2]. While this entry describes a cellular location rather than a single molecular target, it is the site of action for various drugs that modulate metabolism, such as metformin, or target oxidative stress, such as MitoQ [3]. Dysfunctions within these compartments are implicated in a broad spectrum of pathologies, including Leigh syndrome, Parkinson's disease, and various forms of cancer [4]. Therapeutic interventions often aim to restore mitochondrial bioenergetics or prevent the opening of the mitochondrial permeability transition pore (mPTP) to inhibit apoptosis [5]. [1] StatPearls, Physiology, Mitochondrial (https://www.ncbi.nlm.nih.gov/books/NBK553175/); [2] Nature Education, Mitochondria (https://www.nature.com/scitable/topicpage/mitochondria-14053590/); [3] Frontiers in Pharmacology, Mitochondria-Targeted Antioxidants (https://www.frontiersin.org/articles/10.3389/fphar.2020.00529/full); [4] NIH, Mitochondrial Diseases (https://www.ninds.nih.gov/health-information/disorders/mitochondrial-diseases); [5] Journal of Clinical Investigation, Mitochondria as a therapeutic target (https://www.jci.org/articles/view/120842).

Other names

Inner mitochondrial membraneIMMMitochondrial matrixMitochondrial inner compartment

Inhibition of electron transport chain complexes, uncoupling of oxidative phosphorylation, scavenging of mitochondrial reactive oxygen species (ROS), and stabilization of mitochondrial membrane phospholipids like cardiolipin.