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Abstract Background Induction of cellulase in cellulolytic fungi Trichoderma reesei is strongly activated by cellulosic carbon sources. The transport of cellulosic inducer and the perception of inducing signal is generally considered as the critical process for cellulase induction, that the inducing signal would be perceived by a sugar transporter/transceptor in T. reesei. Several sugar transporters are coexpressed during the induction stage, but which function they serve and how they work collaboratively are still difficult to elucidate. Results In this study, we found that the constitutive expression of the cellulose response transporter-like protein CRT2 (previously identified as putative lactose permease TRE77517) improves cellulase induction on a cellulose, cellobiose or lactose medium. Functional studies indicate that the membrane-bound CRT2 is not a transporter of cellobiose, lactose or glucose in a yeast system, and it also does not affect cellobiose and lactose utilization in T. reesei. Further study reveals that CRT2 has a slightly similar function to the cellobiose transporter CRT1 in cellulase induction. Overexpression of CRT2 led to upregulation of CRT1 and the key transcription factor XYR1. Moreover, overexpression of CRT2 could partially compensate for the function loss of CRT1 on cellulase induction. Conclusions Our study uncovers the novel function of CRT2 in cellulase induction collaborated with CRT1 and XYR1, possibly as a signal transductor. These results deepen the understanding of the influence of sugar transporters in cellulase production.

Background: Induction of cellulase in cellulolytic fungi Trichoderma reesei is strongly activated by cellulosic carbon sources. The transport of cellulosic inducer and the perception of inducing signal is generally considered as the critical process for cellulase induction, that the inducing signal would be perceived by a sugar transporter/transceptor in T. reesei. Several sugar transporters are coexpressed during the induction stage, but which function they serve and how they work collaboratively are still difficult to elucidate. Results: In this study, we found that the constitutive expression of the cellulose response transporter-like protein CRT2 (previously identified as putative lactose permease TRE77517) improves cellulase induction on a cellulose, cellobiose or lactose medium. Functional studies indicate that the membrane-bound CRT2 is not a transporter of cellobiose, lactose or glucose in a yeast system, and it also does not affect cellobiose and lactose utilization in T. reesei. Further study reveals that CRT2 has a slightly similar function to the cellobiose transporter CRT1 in cellulase induction. Overexpression of CRT2 led to upregulation of CRT1 and the key transcription factor XYR1. Moreover, overexpression of CRT2 could partially compensate for the function loss of CRT1 on cellulase induction. Conclusions: Our study uncovers the novel function of CRT2 in cellulase induction collaborated with CRT1 and XYR1, possibly as a signal transductor. These results deepen the understanding of the influence of sugar transporters in cellulase production. [ABSTRACT FROM AUTHOR]

The present research investigated the reason for mixed evidence concerning the relationship between analytic cognitive style (ACS) and political orientation in previous research. Most past research operationalized ACS with the Cognitive Reflection Test (CRT), which has been criticized as relying heavily on numeracy skills, and operationalized political orientation with the single-item self-placement measure, which has been criticized as masking the distinction between social and economic conservatism. The present research recruited an Amazon Mechanical Turk sample and, for the first time, simultaneously employed three separate ACS measures (CRT, CRT2, Baserate conflict problems), a measure of attitudes toward self-critical and reflective thinking (the Actively Open-Minded Thinking Scale; AOT), and separate measures of social and economic conservatism, as well the standard measure of political orientation. As expected, the total ACS score (combination of the separate measures) was negatively related to social, but not economic, conservatism. However, the CRT by itself was not related to conservatism, in parallel with some past findings, while the two other measures of ACS showed the same pattern as the combined score. Trait reflectiveness (AOT) was related negatively to all measures of political conservatism (social, economic, and general). Results clearly suggest that the conclusion reached regarding the ACS-political orientation relationship depends on the measure(s) used, with the measure most commonly employed in past research (CRT) behaving differently than other measures. Future research must further pursue the implications of the known differences (e.g., reliance on numeracy vs.\ verbal skills) of ACS measures and distinguish different senses of reflectiveness. % changes in abstract Keywords: analytic cognitive style, actively open-minded thinking, social conservatism, economic conservatism, political orientation, dual-process model, cognitive reflection test.