bims-micpro Biomed News
on Discovery and characterization of microproteins
Issue of 2022‒09‒25
three papers selected by
Thomas Farid Martínez
University of California, Irvine

  1. Mol Psychiatry. 2022 Sep 21.
      Mitochondrial DNA variants have previously associated with disease, but the underlying mechanisms have been largely elusive. Here, we report that mitochondrial SNP rs2853499 associated with Alzheimer's disease (AD), neuroimaging, and transcriptomics. We mapped rs2853499 to a novel mitochondrial small open reading frame called SHMOOSE with microprotein encoding potential. Indeed, we detected two unique SHMOOSE-derived peptide fragments in mitochondria by using mass spectrometry-the first unique mass spectrometry-based detection of a mitochondrial-encoded microprotein to date. Furthermore, cerebrospinal fluid (CSF) SHMOOSE levels in humans correlated with age, CSF tau, and brain white matter volume. We followed up on these genetic and biochemical findings by carrying out a series of functional experiments. SHMOOSE acted on the brain following intracerebroventricular administration, differentiated mitochondrial gene expression in multiple models, localized to mitochondria, bound the inner mitochondrial membrane protein mitofilin, and boosted mitochondrial oxygen consumption. Altogether, SHMOOSE has vast implications for the fields of neurobiology, Alzheimer's disease, and microproteins.
  2. Mol Cancer. 2022 Sep 19. 21(1): 181
      BACKGROUND: Although, micropeptides encoded by non-coding RNA have been shown to have an important role in a variety of tumors processes, there have been no reports on micropeptide in renal cell carcinoma (RCC). Based on the micropeptide MIAC (micropeptide inhibiting actin cytoskeleton) discovered and named in the previous work, this study screened its tumor spectrum, and explored its mechanism of action and potential diagnosis and treatment value in the occurrence and development of renal carcinoma.METHODS: The clinical significance of MIAC in RCC was explored by bioinformatics analysis through high-throughput RNA-seq data from 530 patients with kidney renal clear cell carcinoma (KIRC) in the TCGA database, and the detection of clinical samples of 70 cases of kidney cancer. In vitro and in vivo experiments to determine the role of MIAC in renal carcinoma cell growth and metastasis; High-throughput transcriptomics, western blotting, immunoprecipitation, molecular docking, affinity experiments, and Streptavidin pulldown experiments identify MIAC direct binding protein and key regulatory pathways.
    RESULTS: The analysis of 600 renal carcinoma samples from different sources revealed that the expression level of MIAC is significantly decreased, and corelated with the prognosis and clinical stage of tumors in patients with renal carcinoma. Overexpression of MIAC in renal carcinoma cells can significantly inhibit the proliferation and migration ability, promote apoptosis of renal carcinoma cells, and affect the distribution of cells at various stages. After knocking down MIAC, the trend is reversed. In vivo experiments have found that MIAC overexpression inhibit the growth and metastasis of RCC, while the synthetized MIAC peptides can significantly inhibit the occurrence and development of RCC in vitro and in vivo. Further mechanistic studies have demonstrated that MIAC directly bind to AQP2 protein, inhibit EREG/EGFR expression and activate downstream pathways PI3K/AKT and MAPK to achieve anti-tumor effects.
    CONCLUSIONS: This study revealed for the first time the tumor suppressor potential of the lncRNA-encoded micropeptide MIAC in RCC, which inhibits the activation of the EREG/EGFR signaling pathway by direct binding to AQP2 protein, thereby inhibiting renal carcinoma progression and metastasis. This result emphasizes that the micropeptide MIAC can provide a new strategy for the diagnosis and treatment of RCC.
    Keywords:  Aquaporin 2; EREG/EGFR pathway; MIAC; Micropeptides; Non-coding RNA; Renal cell carcinoma
  3. Sheng Wu Gong Cheng Xue Bao. 2022 Sep 25. 38(9): 3194-3214
      Long non-coding RNA (lncRNA) refers to non-coding RNA longer than 200 nt, with one or more short open reading frames (sORF), which encode functional micro-peptides. These functional micro-peptides often play key roles in various biological processes, such as Ca2+ transport, mitochondrial metabolism, myocyte fusion, cellular senescence and others. At the same time, these biological processes play a key role in the regulation of body homeostasis, diseases and cancers development and progression, embryonic development and other important physiological processes. Therefore, studying the potential regulatory mechanisms of micro-peptides encoded by lncRNA in organisms will help to further elucidate the potential regulatory processes in organisms. Furthermore, it will provide a new theoretical basis for the subsequent targeted treatment of diseases and improvement of animal growth performance. This review summarizes the latest research progress in the field of lncRNA-encoded micro-peptides, as well as the progress in the fields of muscle physiological regulation, inflammation and immunity, common human cancers, and embryonic development. Finally, the challenges of lncRNA-encoded micro-peptides are briefly described, with the aim to facilitate subsequent in-depth research on micro-peptides.
    Keywords:  cancer; embryonic development; inflammation; long non-coding RNA; micro-peptide; muscle physiology; short open reading frames