Related Experiment Video

Updated: Aug 15, 2026

Methods for In situ Quantification of Mitochondrial Morphology in Muscle and Terminal Schwann Cells of Mice
08:13

Methods for In situ Quantification of Mitochondrial Morphology in Muscle and Terminal Schwann Cells of Mice

Published on: April 10, 2026

MIDAS/GPP34, a nuclear gene product, regulates total mitochondrial mass in response to mitochondrial dysfunction

Naomi Nakashima-Kamimura1, Sadamitsu Asoh, Yoshitomo Ishibashi

  • 1Department of Biochemistry and Cell Biology, Institute of Development and Aging Sciences, Graduate School of Medicine, Nippon Medical School, 1-396 Kosugi-cho, Kawasaki, Kanagawa 211-8533, Japan.

Journal of Cell Science
|November 3, 2005
PubMed

Insights

Researchers discovered MIDAS (mitochondrial DNA absence sensitive factor), a protein that regulates mitochondrial mass by controlling cardiolipin levels. Its expression increases with mitochondrial dysfunction, suggesting a role in cellular adaptation.

Area of Science:

  • Cell Biology
  • Mitochondrial Biology
  • Molecular Biology

Background:

  • Mitochondrial biogenesis involves complex signaling between mitochondria and the nucleus.
  • The precise regulatory mechanisms, especially in response to mitochondrial dysfunction, remain incompletely understood.

Purpose of the Study:

  • To identify and characterize novel factors involved in the regulation of mitochondrial biogenesis.
  • To investigate the function of a newly identified factor, MIDAS (mitochondrial DNA absence sensitive factor), in response to mitochondrial stress.

Main Methods:

  • Utilized HeLa cells for expression studies of MIDAS.
  • Employed stable transfection with MIDAS cDNA and siRNA to modulate its levels.
  • Analyzed mitochondrial mass, cardiolipin content, and levels of mitochondrial DNA, RNA, and proteins.

Main Results:

  • MIDAS expression is upregulated in the absence of mitochondrial DNA (mtDNA) and in dysfunctional muscle fibers of patients with mitochondrial diseases.
  • MIDAS primarily localizes to mitochondria, with a smaller fraction in the Golgi apparatus.
  • Overexpression of MIDAS increased mitochondrial mass and cardiolipin levels, while MIDAS knockdown decreased them.
  • Mitochondrial DNA, RNA, and protein levels were independent of MIDAS.

Conclusions:

  • MIDAS plays a crucial role in regulating mitochondrial mass through modulation of mitochondrial lipids, specifically cardiolipin.
  • MIDAS acts as a sensor for mitochondrial dysfunction, contributing to adaptive increases in mitochondrial mass.

Related Concept Videos

Animal Mitochondrial Genetics02:59

Animal Mitochondrial Genetics

Among all the organelles in an animal cell, only mitochondria have their own independent genomes. Animal mitochondrial DNA is a double-stranded, closed-circular molecule with around 20,000 base pairs. Mitochondrial DNA is unique in that one of its two strands, the heavy, or H, -strand is guanine rich, whereas the complementary strand is cytosine rich and called the light, or L, -strand. Compared to nuclear DNA, mitochondrial DNA has a very low percentage of non-coding regions and is marked by...
Mitochondria01:37

Mitochondria

Mitochondria are eukaryotic cellular organelles that are known to produce energy through a process called oxidative phosphorylation. Besides their primary function, mitochondria are involved in various cellular processes, including cell growth, differentiation, signaling, metabolism, and senescence. Age-related changes cause a decline in mitochondrial quality and integrity due to increased mitochondrial mutations and oxidative damage. Thus, aging can severely impact mitochondrial functions,...
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,...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...
Mitochondrial Membranes01:45

Mitochondrial Membranes

A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...