Regulation of mitochondrial morphology and cell survival by Mitogenin I and mitochondrial single-stranded DNA binding protein.
We found that a mouse homolog of human DNA polymerase delta interacting protein 38, referred to as Mitogenin I in this paper, and mitochondrial single-stranded DNA-binding protein (mtSSB), identified as upregulated genes in the heart of mice with juvenile visceral steatosis, play a role in the regulation of mitochondrial morphology. We demonstrated that overexpression of Mitogenin I or mtSSB increased elongated or fragmented mitochondria in mouse C2C12 myoblast cells, respectively. On the other hand, the silencing of Mitogenin I or mtSSB by RNA interference led to an increase in fragmented or elongated mitochondria in the cells, respectively, suggesting that Mitogenin I and mtSSB are involved in the processes of mitochondrial fusion and fission, respectively. In addition, we showed that the silencing of Mitogenin I resulted in an increase in the number of trypan blue-positive cells and the silencing of mtSSB resulted in an enhancement of the sensitivity of the cells to apoptotic stimulation by etoposide. The present results demonstrated that these proteins play a role in cell survival.
Arakaki
Naokatu
N
Department of Molecular Cell Biology and Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima 770-8505, Japan. arakaki@ph.tokushima-u.ac.jp
Nishihama
Takeshi
T
Kohda
Akira
A
Owaki
Hiroyuki
H
Kuramoto
Yoshinori
Y
Abe
Reika
R
Kita
Toshiyuki
T
Suenaga
Midori
M
Himeda
Toshiki
T
Kuwajima
Masamichi
M
Shibata
Hirofumi
H
Higuti
Tomihiko
T
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D051379:Mice; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins
D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; D009687:Nuclear Proteins; C514737:mitogenin 1 protein, mouse; C484072:mtSSB protein, mouse