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Updated: Sep 14, 2025

Mitochondria-associated ER Membranes MAMs and Glycosphingolipid Enriched Microdomains GEMs: Isolation from Mouse Brain
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Role of Mitochondria-Associated ER in Apoptosis

Mudan Sang1,2, Xindong Li1,2, Mi Chen1,2

  • 1College of Animal Science, Xizang Agriculture and Animal Husbandry University, Xizang, People's Republic of China.

Cell Biochemistry and Function
|July 22, 2025
PubMed

Insights

Mitochondria-associated ER membranes (MAMs) coordinate cell death pathways by regulating calcium signaling and mitochondrial dynamics. MAMs

Area of Science:

  • Cell Biology
  • Biochemistry
  • Physiology

Background:

  • Apoptosis is a crucial noninflammatory cell clearance mechanism regulated by proapoptotic and antiapoptotic signaling.
  • Key apoptotic pathways include intrinsic, extrinsic, and ER-stress pathways.
  • Mitochondria-associated ER membranes (MAMs) are critical platforms linking mitochondria and ER, regulating calcium homeostasis and apoptosis.

Purpose of the Study:

  • To systematically review the structural dynamics of MAMs and their influence on calcium signaling and protein expression.
  • To examine the roles of MAMs-tethered proteins in calcium homeostasis, lipid metabolism, and mitochondrial dynamics.
  • To elucidate the impact of mitochondrial dynamics on Bax/Drp1 dimerization during apoptosis.

Main Methods:

  • Review of existing literature on apoptosis, MAMs structure and function, and related molecular mechanisms.
  • Analysis of protein complexes at MAMs, including IP3Rs-Grp75-VDAC1, Mfn1/Mfn2, and PTPIP51 complexes.
  • Investigation of MAMs' role in calcium trafficking, lipid metabolism, and mitochondrial morphology.

Main Results:

  • MAMs' structural dynamics (gap width, contact number) modulate calcium trafficking and tethering protein expression.
  • MAMs-tethered proteins regulate calcium homeostasis, lipid synthesis/transport, and mitochondrial morphology and dynamics.
  • MAMs-mediated mitochondrial dynamics, including fission and cristae remodeling, promote apoptosis via Bax/Drp1 dimerization.

Conclusions:

  • MAMs are central regulators of apoptosis, integrating signals through calcium homeostasis, lipid metabolism, and mitochondrial dynamics.
  • Dynamic alterations in MAMs structure and function are critical for apoptotic pathway activation.
  • Understanding MAMs' role provides insights into cellular mechanisms of programmed cell death.
Keywords:
Bcl‐2 family proteinsapoptosismitochondrial dynamicsmitochondria‐associated ERtether proteins

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