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Ubl4A is critical for mitochondrial fusion process under nutrient deprivation stress

Zhang, Huaiyuan ; Zhao, Yu ; Yao, Qi ; Ye, Zijing ; Mañas, Adriana LU and Xiang, Jialing (2020) In PLoS ONE 15(11).
Abstract

Mitochondrial fusion and fission are dynamic processes regulated by the cellular microenvironment. Under nutrient starvation conditions, mitochondrial fusion is strengthened for energy conservation. We have previously shown that newborns of Ubl4A-deficient mice were more sensitive to starvation stress with a higher rate of mortality than their wild-type littermates. Ubl4A binds with the actin-related protein Arp2/3 complex to synergize the actin branching process. Here, we showed that deficiency in Ubl4A resulted in mitochondrial fragmentation and apoptosis. A defect in the fusion process was the main cause of the mitochondrial fragmentation and resulted from a shortage of primed Arp2/3 complex pool around the mitochondria in the... (More)

Mitochondrial fusion and fission are dynamic processes regulated by the cellular microenvironment. Under nutrient starvation conditions, mitochondrial fusion is strengthened for energy conservation. We have previously shown that newborns of Ubl4A-deficient mice were more sensitive to starvation stress with a higher rate of mortality than their wild-type littermates. Ubl4A binds with the actin-related protein Arp2/3 complex to synergize the actin branching process. Here, we showed that deficiency in Ubl4A resulted in mitochondrial fragmentation and apoptosis. A defect in the fusion process was the main cause of the mitochondrial fragmentation and resulted from a shortage of primed Arp2/3 complex pool around the mitochondria in the Ubl4A-deficient cells compared to the wild-type cells. As a result, the mitochondrial fusion process was not undertaken quickly enough to sustain starvation stress-induced cell death. Consequently, fragmented mitochondria lost their membrane integrity and ROS was accumulated to trigger caspase 9-dependent apoptosis before autophagic rescue. Furthermore, the wild-type Ubl4A, but not the Arp2/3-binding deficient mutant, could rescue the starvation-induced mitochondrial fragmentation phenotype. These results suggest that Ubl4A promotes the mitochondrial fusion process via Arp2/3 complex during the initial response to nutrient deprivation for cell survival.

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author
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publishing date
type
Contribution to journal
publication status
published
subject
in
PLoS ONE
volume
15
issue
11
article number
e0242700
publisher
Public Library of Science (PLoS)
external identifiers
  • pmid:33211772
  • scopus:85096459417
ISSN
1932-6203
DOI
10.1371/journal.pone.0242700
language
English
LU publication?
no
id
c10e45f0-bf3f-4dc4-a9ed-83d8cbd94a71
date added to LUP
2020-11-23 09:16:49
date last changed
2024-04-17 20:29:28
@article{c10e45f0-bf3f-4dc4-a9ed-83d8cbd94a71,
  abstract     = {{<p>Mitochondrial fusion and fission are dynamic processes regulated by the cellular microenvironment. Under nutrient starvation conditions, mitochondrial fusion is strengthened for energy conservation. We have previously shown that newborns of Ubl4A-deficient mice were more sensitive to starvation stress with a higher rate of mortality than their wild-type littermates. Ubl4A binds with the actin-related protein Arp2/3 complex to synergize the actin branching process. Here, we showed that deficiency in Ubl4A resulted in mitochondrial fragmentation and apoptosis. A defect in the fusion process was the main cause of the mitochondrial fragmentation and resulted from a shortage of primed Arp2/3 complex pool around the mitochondria in the Ubl4A-deficient cells compared to the wild-type cells. As a result, the mitochondrial fusion process was not undertaken quickly enough to sustain starvation stress-induced cell death. Consequently, fragmented mitochondria lost their membrane integrity and ROS was accumulated to trigger caspase 9-dependent apoptosis before autophagic rescue. Furthermore, the wild-type Ubl4A, but not the Arp2/3-binding deficient mutant, could rescue the starvation-induced mitochondrial fragmentation phenotype. These results suggest that Ubl4A promotes the mitochondrial fusion process via Arp2/3 complex during the initial response to nutrient deprivation for cell survival.</p>}},
  author       = {{Zhang, Huaiyuan and Zhao, Yu and Yao, Qi and Ye, Zijing and Mañas, Adriana and Xiang, Jialing}},
  issn         = {{1932-6203}},
  language     = {{eng}},
  month        = {{11}},
  number       = {{11}},
  publisher    = {{Public Library of Science (PLoS)}},
  series       = {{PLoS ONE}},
  title        = {{Ubl4A is critical for mitochondrial fusion process under nutrient deprivation stress}},
  url          = {{http://dx.doi.org/10.1371/journal.pone.0242700}},
  doi          = {{10.1371/journal.pone.0242700}},
  volume       = {{15}},
  year         = {{2020}},
}