Sugars, such as sucrose and glucose, have been implicated in the regulation of diverse developmental events in plants and other organisms. We isolated an Arabidopsis (Arabidopsis thaliana) mutant, sugar-insensitive3 (sis3), that is resistant to the inhibitory effects of high concentrations of exogenous glucose and sucrose on early seedling development. In contrast to wildtype plants, sis3 mutants develop green, expanded cotyledons and true leaves when sown on medium containing high concentrations (e.g. 270 mM) of sucrose. Unlike some other sugar response mutants, sis3 exhibits wild-type responses to the inhibitory effects of abscisic acid and paclobutrazol, a gibberellic acid biosynthesis inhibitor, on seed germination. Map-based cloning revealed that SIS3 encodes a RING finger protein. Complementation of the sis3-2 mutant with a genomic SIS3 clone restored sugar sensitivity of sis3-2, confirming the identity of the SIS3 gene. Biochemical analyses demonstrated that SIS3 is functional in an in vitro ubiquitination assay and that the RING motif is sufficient for its activity. Our results indicate that SIS3 encodes a ubiquitin E3 ligase that is a positive regulator of sugar signaling during early seedling development.Almost all living organisms rely on the products of plant photosynthesis for sustenance, either directly or indirectly. Carbohydrates, the major photosynthates, provide both energy and carbon skeletons for fungi, plants, and animals. In addition, sugars, such as Suc and Glc, function as signaling molecules to regulate plant growth, development, gene expression, and metabolic processes. Sugar response pathways are integrated with other signaling pathways, such as those for light, phytohormones, stress, and nitrogen (Dijkwel et al

Disparities in undergraduate STEM degree completion across different racial/ethnic groups have been a topic of increasing national concern. This study investigates the long-term outcomes of a STEM intervention program designed to increase the academic preparation, achievement and persistence of under-represented minority students.In particular, this study examines the extent to which participation in a STEM intervention program can impact the long-term persistence and graduation of first-time in college under-represented minority students. Using discrete-time competing risks analysis, results demonstrated that participants of the intervention program had a lower probability of drop out and higher probability of persisting in a STEM field of study compared to non-participants of the program. Additionally, descriptive results demonstrated that participants of the STEM intervention program had higher rates of graduation in any field compared to non-participants of the program, while program participation was not a significant predictor of six-year graduation. Findings highlight the importance of early academic preparation in Calculus and total credit accumulation to student success outcomes of URM students enrolled in STEM fields. Recommendations from this study focus on early intervention efforts, particularly in the areas of mathematics, that ensure URM students are adequately prepared with the skills needed to succeed in a STEM field of study.

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A comprehensive gene collection for S. oneidensis was constructed using the lambda recombinase (Gateway) cloning system. A total of 3584 individual ORFs (85%) have been successfully cloned into the entry plasmids. To validate the use of the clone set, three sets of ORFs were examined within three different destination vectors constructed in this study. Success rates for heterologous protein expression of S. oneidensis His- or His/GST- tagged proteins in E. coli were approximately 70%. The ArcA and NarP transcription factor proteins were tested in an in vitro binding assay to demonstrate that functional proteins can be successfully produced using the clone set. Further functional validation of the clone set was obtained from phage display experiments in which a phage encoding thioredoxin was successfully isolated from a pool of 80 different clones after three rounds of biopanning using immobilized anti-thioredoxin antibody as a target. This clone set complements existing genomic (e.g., whole-genome microarray) and other proteomic tools (e.g., mass spectrometry-based proteomic analysis), and facilitates a wide variety of integrated studies, including protein expression, purification, and functional analyses of proteins both in vivo and in vitro.