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As a core subunit of the SCF complex that promotes protein degradation through the 26S proteasome, S-phase kinase-associated protein 1 (SKP1) plays important roles in multiple cellular processes in eukaryotes, including gibberellin (GA), jasmonate, ethylene, auxin and light responses. P7-2 encoded by Rice black streaked dwarf virus (RBSDV), a devastating viral pathogen that causes severe symptoms in infected plants, interacts with SKP1 from different plants. However, whether RBSDV P7-2 forms a SCF complex and targets host proteins is poorly understood. In this study, we conducted yeast two-hybrid assays to further explore the interactions between P7-2 and 25 type I Oryza sativa SKP1-like (OSK) proteins, and found that P7-2 interacted with eight OSK members with different binding affinity. Co-immunoprecipitation assay further confirmed the interaction of P7-2 with OSK1, OSK5 and OSK20. It was also shown that P7-2, together with OSK1 and O. sativa Cullin-1, was able to form the SCF complex. Moreover, yeast two-hybrid assays revealed that P7-2 interacted with gibberellin insensitive dwarf2 (GID2) from rice and maize plants, which is essential for regulating the GA signaling pathway. It was further demonstrated that the N-terminal region of P7-2 was necessary for the interaction with GID2. Overall, these results indicated that P7-2 functioned as a component of the SCF complex in rice, and interaction of P7-2 with GID2 implied possible roles of the GA signaling pathway during RBSDV infection. [ABSTRACT FROM AUTHOR]

NFATs are transcription factors involved in immune activation and tumor progression. Previous reports showed that DYRK1A suppressed NFATc2 transcriptional activity through phosphorylation. Nonetheless, our results showed that DYRK1A increased NFATc1/αA protein level and subsequent transcriptional activity. DYRK1A phosphorylation of NFATc1/αA at S261, S278, S403 and S409 interfered with NFATc1 ubiquitination and ubiquitin-proteasome degradation. Our results imply that DYRK1A is a positive kinase in regulation of NFATc1. [ABSTRACT FROM AUTHOR]

This study is aimed to assess the biodegradation of sulfadiazine (SDZ) and characterization of heavy metal resistance in three pure bacterial cultures and also their chemotactic response towards 2-aminopyrimidine. The bacterial cultures were isolated from pig manure, activated sludge and sediment samples, by enrichment technique on SDZ (6 mg L-1). Based on the 16S rRNA gene sequence analysis, the microorganisms were identified within the genera of Paracoccus, Methylobacterium and Kribbella, which were further designated as SDZ-PM2-BSH30, SDZ-W2-SJ40 and SDZ-3S-SCL47. The three identified pure bacterial strains degraded up to 50.0, 55.2 and 60.0% of SDZ (5 mg L-1), respectively within 290 h. On the basis of quadrupole time-of-flight mass spectrometry and high performance liquid chromatography, 2-aminopyrimidine and 4-hydroxy-2-aminopyrimidine were identified as the main intermediates of SDZ biodegradation. These bacteria were also able to degrade the metabolite, 2-aminopyrimidine, of the SDZ. Furthermore, SDZ-PM2-BSH30, SDZ-W2-SJ40 and SDZ-3S-SCL47 also showed resistance to various heavy metals like copper, cadmium, chromium, cobalt, lead, nickel and zinc. Additionally, all three bacteria exhibited positive chemotaxis towards 2-aminopyrimidine based on the drop plate method and capillary assay. The results of this study advanced our understanding about the microbial degradation of SDZ, which would be useful towards the future SDZ removal in the environment. [ABSTRACT FROM AUTHOR]