光敏色素互作因子PIFs是整合多种信号调控植物生长发育的核心元件

光敏色素互作因子（PIFs）蛋白家族隶属于bHLH转录因子家族,参与多种信号转导途径,调控植物的生长发育进程,如抑制种子萌发、促进幼苗的暗形态建成和调控开花时间等。作为一个胞内信号调控的重要组分,PIFs广泛参与到由多种植物内源激素如赤霉素、乙烯、生长素、油菜素内酯、脱落酸和外部环境因素如高温、光等所介导的信号网络中。本文AKPIFs的结构、参与途径及调控植物发育进程3个方面,简要介绍近年来国内外对PIFs在信号网络调控方面的最新研究进展。     

Convergence of signaling pathways in the control of differential cell growth in Arabidopsis

Seedling apical hook development involves a complex interplay of hormones and light in the regulation of differential cell growth. However, the underlying molecular mechanisms that integrate these diverse signals to control bending of the embryonic stem are poorly understood. The Arabidopsis ethylene-regulated HOOKLESS1 (HLS1) gene is essential for apical hook formation. Herein, we identify two auxin response regulators that act downstream of HLS1 to control cell elongation in the hypocotyl. Extragenic suppressors of hls1 were identified as mutations in AUXIN RESPONSE FACTOR 2 (ARF2). The level of ARF2 protein was decreased by ethylene, and this response required HLS1. Exposure to light decreased HLS1 protein levels and evoked a concomitant increase in ARF2 accumulation. These studies demonstrate that both ethylene and light signals affect differential cell growth by acting through HLS1 to modulate the auxin response factors, pinpointing HLS1 as a key integrator of the signaling pathways that control hypocotyl bending.     

FoxO转录因子的活性调节及对哺乳动物细胞进程的调控

FoxO转录因子在哺乳动物的细胞分化、增殖和细胞存活中发挥着重要调控作用,其转录活性受PI3K通路、非PI3K依赖通路、乙酰化和泛素化作用等多种途径调控.FoxO受到上游信号分子PI3K/Akt、SGK等的激活,调节靶基因的转录,从而调节哺乳动物细胞周期的进程和凋亡事件.FoxO已成为肿瘤、癌症科学研究的热点之一.