The Role of Microtubules in the Trafficking of Ectopic ATP Synthase
Ontology highlight
ABSTRACT: Adenosine triphosphate (ATP) synthase is located on the inner membrane of mitochondria which generate ATP for various cellular processes. Our previous studies showed that ATP synthases existed on plasma membrane of several types of cancer cells, which was defined as ectopic ATP synthase. However, the trafficking pathway of ectopic ATP synthase is still unclear. To investigate how ATP synthase subunits are involved in the trafficking process, we performed shot-gun proteomic analysis to reveal the plasma membrane proteins of A549 lung cancer cells and identified four subunits of ATP synthases, ATP5A1, ATP5B, ATP5H, and MT-ATP6. With the results of gene set enrichment analysis, we inferred that ectopic ATP synthase subunits are assembled as complex consistently and then translocated to cell surface through the trafficking of mitochondria. On the other hand, microtubules are involved in many intracellular transport. During protein trafficking, mitochondria and vesicles are transported to their final destination along microtubules by motor proteins such as kinesins and dyneins. To explore the function of microtubules in the trafficking of ectopic ATP synthase, we treated MCF-7 breast and A549 lung cancer cells with nocodazole, a microtubule depolymerization agent, and found that the expression level of ectopic ATP synthase decreased using both immunocytochemistry and flow cytometry. Besides, since kinesin family member 5B (KIF5B) is an important motor proteins involved in the transport of mitochondria, we further performed the immunoprecipitation of KIF5B followed by liquid chromatography−tandem mass spectrometry (LC−MS/MS). The result revealed that one of the mitochondrial outer membrane proteins, dynamin-1 like proteins (Drp1), was able to associate to KIF5B. From our recent research results and other reports show that Drp1 is a mediator of mitochondrial dynamic through regulation of mitochondrial fission. Taken together, our findings suggested that Drp1-KIF5B complex-mediated mitochondrial trafficking along microtubules may play a critical role in the transport of ectopic ATP synthase
INSTRUMENT(S): LTQ Orbitrap
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Epithelial Cell, Cell Culture
SUBMITTER: Ting-Yu Huang
LAB HEAD: Hsueh-Fen Juan
PROVIDER: PXD006791 | Pride | 2023-05-10
REPOSITORIES: Pride
ACCESS DATA