Validation of Nuclear Pore Complex Protein-Protein Interactions by Transient Expression in Plants.

The nuclear pore complex (NPC) is the largest protein complex, consisting of multiple copies of over 30 different nucleoporins. The interactions between the nucleoporins are critical elements for the NPC functions of the nuclear envelope in plant cells. In recent years, transient expression-based validations of protein-protein interactions have been widely used in plants. Bimolecular fluorescence complementation assay and coimmunoprecipitation assays are powerful tools to identify the molecules that interact with specific proteins. Here, as an example, we describe these techniques using nucleoporin protein interactions in plants.

Effect of growth temperature on monoterpene emission rates of Acer palmatum.

To understand the effect of increasing atmospheric temperatures on monoterpene emissions from mature trees, we measured the monoterpene emission rate, monoterpene precursor content, and the SPAD value of Acer palmatum, a mature tree grown at three different field sites. The annual mean temperature differed by intervals of 3 °C among the three sites from 10.6 °C to 17.7 °C, depending on the site elevation. The short-term monoterpene emission rate of A. palmatum depended on both the leaf temperature and the light intensity. The growth temperature did not affect the monoterpene emissions in response to short-term variations in temperature and light intensity. The highest standard monoterpene emission rate, Ms, was observed from July to August, but this rate did not differ among the three sites. The Ms showed clear seasonal variation, whereas the monoterpene precursor content did not show them. The trend of the Ms was similar to that of the SPAD, as both values depend on leaf phenology. In A. palmatum, a warming of approximately 3 °C caused the start date of the monoterpene emissions to commence two to three weeks earlier, and end date of the monoterpene emissions to be delayed by two to three weeks. The cumulative temperature method could be used to predict the start and end dates of the monoterpene emissions. To estimate the annual monoterpene emissions, a temperature and light intensity dependent emission model was modified to incorporate the effect of growth temperature on seasonal patterns of Ms. Annual monoterpene emissions were found to increase linearly with annual mean temperature. For each 1 °C of warming, the annual monoterpene emissions from A. palmatum increased by approximately 15%. Our results suggest that the effect of growth temperature on monoterpene emissions should be considered when predicting monoterpene emissions in response to global warming in the foreseeable future.

Gene alterations involving the CRLF2-JAK pathway and recurrent gene deletions in Down syndrome-associated acute lymphoblastic leukemia in Japan.

In Western countries, gene alterations involving the CRLF2-JAK signaling pathway are identified in approximately 50-60% of patients with Down syndrome-associated acute lymphoblastic leukemia (DS-ALL), and this pathway is considered a potential therapeutic target. The frequency of BTG1 deletions in DS-ALL is controversial. IKZF1 deletions, found in 20-30% of DS-ALL patients, are associated with a poor outcome and EBF1 deletions are very rare (∼2%). We analyzed 38 patients to determine the frequencies and clinical implications of CRLF2-JAK pathway genetic alterations and recurrent gene deletions in Japanese DS-ALL patients. We confirmed a high incidence of P2RY8-CRLF2 (29%) and JAK2 mutations (16%), though the frequency of P2RY8-CRLF2 was slightly lower than that in Western countries (∼50%). BTG1 deletions were common in our cohort (25%). IKZF1 deletions were detected in 25% of patients and associated with shorter overall survival (OS). EBF1 deletions were found at an unexpectedly high frequency (16%), and at a significantly higher level in P2RY8-CRLF2-positive patients than in P2RY8-CRLF2-negative patients (44% vs. 4%, P=0.015). Deletions of CDKN2A/B and PAX5 were common in P2RY8-CRLF2-negative patients (48 and 39%, respectively) but not in P2RY8-CRLF2-positive patients (11% each). Associations between these genetic alterations and clinical characteristics were not observed except for inferior OS in patients with IKZF1 deletions. These results suggest that differences exist between the genetic profiles of DS-ALL patients in Japan and in Western countries, and that P2RY8-CRLF2 and EBF1 deletions may cooperate in leukemogenesis in a subset of Japanese DS-ALL patients.