RESUMO
Individual atmospheric particles can contain mixtures of primary organic aerosol (POA), secondary organic aerosol (SOA), and secondary inorganic aerosol (SIA). To predict the role of such complex multicomponent particles in air quality and climate, information on the number and types of phases present in the particles is needed. However, the phase behavior of such particles has not been studied in the laboratory, and as a result, remains poorly constrained. Here, we show that POA+SOA+SIA particles can contain three distinct liquid phases: a low-polarity organic-rich phase, a higher-polarity organic-rich phase, and an aqueous inorganic-rich phase. Based on our results, when the elemental oxygen-to-carbon (O:C) ratio of the SOA is less than 0.8, three liquid phases can coexist within the same particle over a wide relative humidity range. In contrast, when the O:C ratio of the SOA is greater than 0.8, three phases will not form. We also demonstrate, using thermodynamic and kinetic modeling, that the presence of three liquid phases in such particles impacts their equilibration timescale with the surrounding gas phase. Three phases will likely also impact their ability to act as nuclei for liquid cloud droplets, the reactivity of these particles, and the mechanism of SOA formation and growth in the atmosphere. These observations provide fundamental information necessary for improved predictions of air quality and aerosol indirect effects on climate.
RESUMO
Protein kinase CK2 is a serine/threonine kinase known to phosphorylate numerous substrates. CK2 is implicated in several physiologic and pathologic processes, particularly in cancer biology. CK2 is comprised of several subunits, including CK2alpha, CK2alpha' and CK2beta. Inactivation of CK2alpha' leads to chromatin degeneration of germ cells, resulting in male sterility. To identify additional targets of CK2alpha' in testes and to determine the role of CK2alpha' in germ cell nuclear integrity, GST pull-down and protein-protein interaction assays were conducted. A novel testis-specific gene, CKT2 (CK2 Target protein 2), was found whose product interacts with and is phosphorylated by CK2 in vitro and in vivo. CKT2 is a 30.2 kDa protein with one coiled-coil domain and six putative phosphorylation sites. High expression of CKT2 correlated with chromatin condensation of spermatids in murine testes. Findings reported herein demonstrate that CKT2 is a target protein of native CK2alpha' in testes and suggest that CKT2 plays a role in chromatin regulation of male germ cells.
Assuntos
Caseína Quinase II/metabolismo , Fosfoproteínas/metabolismo , Testículo/metabolismo , Animais , Linhagem Celular , Humanos , Masculino , Camundongos , Proteínas Nucleares/metabolismo , Fosfoproteínas/química , Fosfoproteínas/genética , Fosforilação , Subunidades Proteicas/metabolismo , Espermátides/metabolismo , Testículo/enzimologia , Técnicas do Sistema de Duplo-HíbridoRESUMO
Colorectal cancer often presents as a highly variable disease with myriad forms that are at times difficult to detect in early screenings with sufficient accuracy, for which novel diagnostic methods are an attractive and valuable area of improvement. To improve colorectal cancer diagnosis and prognosis, new biomarkers that can be assembled into a diagnostic panel must be identified, and tRNA-derived small RNAs (tsRNAs) are a particularly interesting and increasingly visible new class of molecules to examine. In this study, small RNA-seq data were profiled for the expression of 104 human tsRNAs in tumor tissue and adjacent normal tissue samples, and a diagnostic model was built based on four differentially expressed tsRNAs: tRF-22-WB86Q3P92, tRF-22-WE8SPOX52, tRF-22-WE8S68L52, tRF-18-8R1546D2. Furthermore, the diagnostic model was validated by two independent validation datasets (AUC was 0.97 and 0.99), and a LASSO model was applied to develop a seven-tsRNA-based risk score model for colorectal cancer prognosis. Finally, a tsRNA-mRNA interaction network was established according to potential mRNA targets predicted by bioinformatic methods. In conclusion, the results suggest that abnormal expression of tsRNA in colorectal cancer may have a functional effect on tumor action and moreover, that some of the tsRNAs identified in this study with diagnostic and prognostic potential could be of clinical significance.