Shannon Nathaniel, Raymond Cory, Palmer Chloe, Homa Silver, Bonini Marcelo, Seward David, Cunniff Brian
Department of Pathology and Laboratory Medicine, University of Vermont Cancer Center, Larner College of Medicine, Burlington, VT 05405, USA.
Department of Medicine and Biochemistry, Feinberg School of Medicine Northwestern University, Chicago, IL 60611, USA.
J Cell Sci. 2025 May 1;138(9). doi: 10.1242/jcs.263554. Epub 2025 Apr 2.
Mitochondrial positioning supports localized energy and signaling requirements. Miro1 is necessary for attachment of mitochondria to microtubule motor proteins for trafficking. When Miro1 is deleted (Miro1-/-) from mouse embryonic fibroblasts (MEFs), mitochondria become sequestered to the perinuclear space, disrupting subcellular signaling gradients. Here, we show that Miro1-/- MEFs grow slower than Miro1+/+ and Miro1-/- MEFs stably re-expressing a Myc-Miro1 plasmid. Miro1-/- MEFs have a decreased percentage of cells in G1 and increased percentage of cells in S phase. We conducted the first ever RNA sequencing experiment dependent upon Miro1 expression and found differentially expressed genes related to MAPK signaling, cell proliferation and migration. ERK1 and ERK2 (ERK1/2, also known as MAPK3 and MAPK1, respectively) phosphorylation is elevated both spatially and temporally following serum stimulation in Miro1-/- MEFs, whereas the expression levels and oxidation of the dual specificity phosphatases (DUSP1-DUSP6) is unchanged. Finally, we found the oxidation status of ERK1/2 is increased in Miro1-/- MEFs compared to that seen in Miro1+/+ and Myc-Miro1 MEFs. These results highlight transcriptional control based off Miro1 expression and demonstrate the dynamic regulation of ERK1/2 upon deletion of Miro1 which might support the observed cell cycle and proliferation defects.
线粒体定位支持局部能量和信号需求。Miro1对于线粒体附着于微管运动蛋白以进行运输是必需的。当从小鼠胚胎成纤维细胞（MEF）中删除Miro1（Miro1-/-）时，线粒体被隔离到核周空间，破坏了亚细胞信号梯度。在这里，我们表明Miro1-/- MEF比Miro1+/+和稳定重新表达Myc-Miro1质粒的Miro1-/- MEF生长得更慢。Miro1-/- MEF中处于G1期的细胞百分比降低，处于S期的细胞百分比增加。我们进行了首次依赖于Miro1表达的RNA测序实验，发现了与MAPK信号传导、细胞增殖和迁移相关的差异表达基因。在Miro1-/- MEF中，血清刺激后ERK1和ERK2（ERK1/2，也分别称为MAPK3和MAPK1）的磷酸化在空间和时间上均升高，而双特异性磷酸酶（DUSP1-DUSP6）的表达水平和氧化状态未改变。最后，我们发现与Miro1+/+和Myc-Miro1 MEF相比，Miro1-/- MEF中ERK1/2的氧化状态增加。这些结果突出了基于Miro1表达的转录控制，并证明了Miro1缺失后ERK1/2的动态调节，这可能支持观察到的细胞周期和增殖缺陷。
