MicroRNAs-103/107 coordinately regulate macropinocytosis and autophagy.
Jong Kook ParkHan PengJulia KatsnelsonWending YangNihal KaplanYing DongJoshua Z RappoportCongCong HeRobert M LavkerPublished in: The Journal of cell biology (2016)
Macropinocytosis, by which cells ingest large amounts of fluid, and autophagy, the lysosome-based catabolic process, involve vesicular biogenesis (early stage) and turnover (end stage). Much is known about early-stage events; however, our understanding of how the end stages of these processes are governed is incomplete. Here we demonstrate that the microRNA-103/107(miR-103/107) family, which is preferentially expressed in the stem cell-enriched limbal epithelium, coordinately regulates aspects of both these activities. Loss of miR-103/107 causes dysregulation of macropinocytosis with the formation of large vacuoles, primarily through up-regulation of Src, Ras, and Ankfy1. Vacuole accumulation is not a malfunction of early-stage autophagy; rather, miR-103/107 ensure proper end-stage autophagy by regulating diacylglycerol/protein kinase C and cyclin-dependent kinase 5 signaling, which enables dynamin to function in vacuole clearance. Our findings unveil a key biological function for miR-103/107 in coordinately suppressing macropinocytosis and preserving end-stage autophagy, thereby contributing to maintenance of a stem cell-enriched epithelium.
Keyphrases
- early stage
- cell death
- cell proliferation
- endoplasmic reticulum stress
- long non coding rna
- stem cells
- signaling pathway
- induced apoptosis
- oxidative stress
- long noncoding rna
- cell cycle arrest
- protein kinase
- tyrosine kinase
- squamous cell carcinoma
- mesenchymal stem cells
- radiation therapy
- lymph node
- bone mineral density
- cell therapy
- rectal cancer