scholarly journals Mitochondrial membrane contact sites of yeast. Characterization of lipid components and possible involvement in intramitochondrial translocation of phospholipids

1991 ◽  
Vol 266 (16) ◽  
pp. 10047-10049
Author(s):  
R. Simbeni ◽  
L. Pon ◽  
E. Zinser ◽  
F. Paltauf ◽  
G. Daum
Keyword(s):  
Mitochondrial Membrane ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Membrane Contact ◽  
Lipid Components

scholarly journals Characterization of Membrane Contact Sites for the Facilitation of Lipid Exchange at the Malaria Parasite - Red Blood Cell Interface

2020 ◽  
Vol 118 (3) ◽  
pp. 574a
Author(s):  
Matthias Garten ◽  
Josh Beck ◽  
Robyn Roth ◽  
John E. Heuser ◽  
Tatyana Tenkova-Heuser ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Malaria Parasite ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Lipid Exchange ◽  
Membrane Contact ◽  
Cell Interface

The ERMES complex and ER–mitochondria connections

2012 ◽  
Vol 40 (2) ◽  
pp. 445-450 ◽  
Author(s):  
Agnès H. Michel ◽  
Benoît Kornmann
Keyword(s):  
Protein Complex ◽  
Biochemical Characterization ◽  
Eukaryotic Cell ◽  
Yeast Protein ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Synthetic Protein ◽  
Membrane Contact ◽  
Cellular Organelles

Cellular organelles need to communicate in order to co-ordinate homoeostasis of the compartmentalized eukaryotic cell. Such communication involves the formation of membrane contact sites between adjacent organelles, allowing privileged exchange of metabolites and information. Using a synthetic protein designed to artificially tether the ER (endoplasmic reticulum) to mitochondria, we have discovered a yeast protein complex naturally involved in establishing and maintaining contact sites between these two organelles. This protein complex is physiologically involved in a plethora of mitochondrial processes, suggesting that ER–mitochondria connections play a central co-ordinating role in the regulation of mitochondrial biology. Recent biochemical characterization of this protein complex led to the discovery that GTPases of the Miro family are part of ER–mitochondria connections. The yeast Miro GTPase Gem1 localizes to ER–mitochondria interface and influences the size and distribution of mitochondria. Thus Miro GTPases may serve as regulators of the ER–mitochondria connection.

scholarly journals Caenorhabditis elegans Junctophilin has tissue-specific functions and regulates neurotransmission with extended-synaptotagmin

Genetics ◽  
2021 ◽  
Author(s):  
Christopher A Piggott ◽  
Zilu Wu ◽  
Stephen Nurrish ◽  
Suhong Xu ◽  
Joshua M Kaplan ◽  
...  
Keyword(s):  
Calcium Channels ◽  
Calcium Channel ◽  
Tissue Specific ◽  
Voltage Gated ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Pharyngeal Muscles ◽  
Membrane Contact ◽  
Null Mutants

Abstract The junctophilin family of proteins tether together plasma membrane (PM) and endoplasmic reticulum (ER) membranes, and couple PM- and ER-localized calcium channels. Understanding in vivo functions of junctophilins is of great interest for dissecting the physiological roles of ER-PM contact sites. Here, we show that the sole C. elegans junctophilin JPH-1 localizes to discrete membrane contact sites in neurons and muscles and has important tissue-specific functions. jph-1 null mutants display slow growth and development due to weaker contraction of pharyngeal muscles, leading to reduced feeding. In the body wall muscle, JPH-1 co-localizes with the PM-localized EGL-19 voltage-gated calcium channel and ER-localized UNC-68/RyR calcium channel, and is required for animal movement. In neurons, JPH-1 co-localizes with the membrane contact site protein Extended-SYnaptoTagmin 2 (ESYT-2) in soma, and is present near presynaptic release sites. Interestingly, jph-1 and esyt-2 null mutants display mutual suppression in their response to aldicarb, suggesting that JPH-1 and ESYT-2 have antagonistic roles in neuromuscular synaptic transmission. Additionally, we find an unexpected cell non-autonomous effect of jph-1 in axon regrowth after injury. Genetic double mutant analysis suggests that jph-1 functions in overlapping pathways with two PM-localized voltage-gated calcium channels, egl-19 and unc-2, and unc-68/RyR for animal health and development. Finally, we show that jph-1 regulates the colocalization of EGL-19 and UNC-68 and that unc-68/RyR is required for JPH-1 localization to ER-PM puncta. Our data demonstrate important roles for junctophilin in cellular physiology, and also provide insights into how junctophilin functions together with other calcium channels in vivo.

scholarly journals Remodelling of Nucleus-Vacuole Junctions During Metabolic and Proteostatic Stress

Contact ◽  
2021 ◽  
Vol 4 ◽  
pp. 251525642110166
Author(s):  
Verena Kohler ◽  
Sabrina Büttner
Keyword(s):  
Nuclear Envelope ◽  
Internal Stress ◽  
Molecular Architecture ◽  
Adaptation To Stress ◽  
Semipermeable Membranes ◽  
Cellular Adaptation ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Intracellular Compartments ◽  
Membrane Contact

Cellular adaptation to stress and metabolic cues requires a coordinated response of different intracellular compartments, separated by semipermeable membranes. One way to facilitate interorganellar communication is via membrane contact sites, physical bridges between opposing organellar membranes formed by an array of tethering machineries. These contact sites are highly dynamic and establish an interconnected organellar network able to quickly respond to external and internal stress by changing size, abundance and molecular architecture. Here, we discuss recent work on nucleus-vacuole junctions, connecting yeast vacuoles with the nucleus. Appearing as small, single foci in mitotic cells, these contacts expand into one enlarged patch upon nutrient exhaustion and entry into quiescence or can be shaped into multiple large foci essential to sustain viability upon proteostatic stress at the nuclear envelope. We highlight the remarkable plasticity and rapid remodelling of these contact sites upon metabolic or proteostatic stress and their emerging importance for cellular fitness.

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