Lamprey PHB2 maintains mitochondrial stability by tanslocation to the mitochondria under oxidative stress

• Published in: Fish & shellfish immunology Vol. 104; pp. 613 - 621
• Main Authors: Shi, Ying, Li, Qing, Sun, Feng, Zhu, Chenyue, Ma, Sainan, Qin, Di, Li, Qingwei, Li, Tiesong
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.09.2020
• Subjects: Animals; Cell Nucleus - metabolism; Fish Proteins - genetics; Fish Proteins - metabolism; Lamprey; Lampreys - genetics; Lampreys - metabolism; Mitochondria; Mitochondria - metabolism; Oxidative Stress; PHB2; Repressor Proteins - genetics; Repressor Proteins - metabolism; Translocation; Translocation, Genetic; Translocation; Oxidative stress; HEK293T; IP; PHB2; Mitochondria; HAX1; OPA1; ROS; HCLS1; Lamprey; IF; QRT-PCR
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2020.06.037

Before we have reported lamprey PHB2 could enhance the cellular oxidative-stressed tolerance, here the aim was to explore its mechanisms. We used flow cytometry analysis to identify a Lampetra morii homologue of PHB2 (Lm-PHB2) that could significantly decrease the levels of ROS generation in HEK293T cells. According to confocal microscopy observations, Lm-PHB2 contributed to maintain the mitochondrial morphology of HEK293T cells, and then both cellular nuclear location and translocation from the nucleus to mitochondria of Lm-PHB2 were also examined in HEK293T cells under oxidative stress. We also examined the expressions and locations of various Lm-PHB2 deletion mutants and the amino acid mutant by confocal microscopy and the results showed that the translocation of Lm-PHB2 into mitochondria was dependent on the Lm-PHB21-50aa region and the 17th, 48th and 57th three arginines (R) of N-terminal were very critical. In addition, the analyses of QRT-PCR and Western blot demonstrated that Lm-PHB2 increased the expression levels of OPA1 and HAX1 in HEK293T cells treated with H2O2. The analyses of immunofluorescence and immunoprecipitation showed that Lm-PHB2 could interact with OPA1 and HAX1, respectively. The above mentioned results indicate that Lm-PHB2 could assist OPA1 and HAX1 to maintain mitochondrial morphology and decrease ROS levels by the translocation from the nucleus to mitochondria under oxidative stress. •Lamprey, as one of the most primitive jawless vertebrate, the PHB2 protein of lamprey can translocalize from the nucleus to mitochondria in HEK293T cell lines under oxidative stress.•Under oxidative stress lamprey PHB2 protein maintains mitochondrial stability by interacting with OPA1 and HAX1 in mitochondria.