Inter-organelle membrane contact sites: through a glass, darkly

2006 ◽  
Vol 18 (4) ◽  
pp. 371-378 ◽  
Author(s):  
Tim Levine ◽  
Chris Loewen
Keyword(s):  
Membrane Contact Sites ◽  
Contact Sites ◽  
Membrane Contact ◽  
Organelle Membrane

scholarly journals Inter-Organelle Membrane Contact Sites and Mitochondrial Quality Control during Aging: A Geroscience View

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 598 ◽  
Author(s):  
Anna Picca ◽  
Riccardo Calvani ◽  
Hélio José Coelho-Junior ◽  
Francesco Landi ◽  
Roberto Bernabei ◽  
...  
Keyword(s):  
Quality Control ◽  
Mitochondrial Dysfunction ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Quality Control ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Age Related ◽  
Bidirectional Communication ◽  
Membrane Contact ◽  
Organelle Membrane

Mitochondrial dysfunction and failing mitochondrial quality control (MQC) are major determinants of aging. Far from being standalone organelles, mitochondria are intricately related with cellular other compartments, including lysosomes. The intimate relationship between mitochondria and lysosomes is reflected by the fact that lysosomal degradation of dysfunctional mitochondria is the final step of mitophagy. Inter-organelle membrane contact sites also allow bidirectional communication between mitochondria and lysosomes as part of nondegradative pathways. This interaction establishes a functional unit that regulates metabolic signaling, mitochondrial dynamics, and, hence, MQC. Contacts of mitochondria with the endoplasmic reticulum (ER) have also been described. ER-mitochondrial interactions are relevant to Ca2+ homeostasis, transfer of phospholipid precursors to mitochondria, and integration of apoptotic signaling. Many proteins involved in mitochondrial contact sites with other organelles also participate to degradative MQC pathways. Hence, a comprehensive assessment of mitochondrial dysfunction during aging requires a thorough evaluation of degradative and nondegradative inter-organelle pathways. Here, we present a geroscience overview on (1) degradative MQC pathways, (2) nondegradative processes involving inter-organelle tethering, (3) age-related changes in inter-organelle degradative and nondegradative pathways, and (4) relevance of MQC failure to inflammaging and age-related conditions, with a focus on Parkinson’s disease as a prototypical geroscience condition.

scholarly journals Inter-organelle membrane contact sites: implications for lipid metabolism

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Jean E. Vance
Keyword(s):  
Endoplasmic Reticulum Membrane ◽  
Biological Functions ◽  
Advantages And Disadvantages ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Experimental Approaches ◽  
Initial Discovery ◽  
Membrane Contact ◽  
Definition Of ◽  
Organelle Membrane

Abstract This article supplements a recent Perspective by Scorrano et al. in Nature Communications [10 [ (1)]:1287] in which the properties and functions of inter-organelle membrane contact sites were summarized. It is now clear that inter-organelle membrane contact sites are widespread in eukaryotic cells and that diverse pairs of organelles can be linked via unique protein tethers. An appropriate definition of what constitutes an inter-organelle membrane contact site was proposed in the Perspective. In addition, the various experimental approaches that are frequently used to study these organelle associations, as well as the advantages and disadvantages of each of these methods, were considered. The nature of the tethers that link the pairs of organelles at the contact sites was discussed in detail and some biological functions that have been ascribed to specific membrane contact sites were highlighted. Nevertheless, the functions of most types of organelle contact sites remain unclear. In the current article I have considered some of the points raised in the Perspective but have omitted detailed information on the roles of membrane contact sites in biological functions such as apoptosis, autophagy, calcium homeostasis and mitochondrial fusion. Instead, I have provided some background on the initial discovery of mitochondria-endoplasmic reticulum membrane contact sites, and have focussed on the known roles of membrane contact sites in inter-organelle lipid transport. In addition, potential roles for membrane contact sites in human diseases are briefly discussed.

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