References and Notes Supporting Online Material Materials and Methods Figs. S1 and S2 Tables S1 to S4 References Protein Friction Limits Diffusive and Directed Movements of Kinesin Motors on Microtubules
References and Notes Supporting Online Material Materials and Methods Figs. S1 and S2 Tables S1 to S4 References Protein Friction Limits Diffusive and Directed Movements of Kinesin Motors on Microtubules
复制标题
DOI：
--
复制
发表时间：
--
期刊：
影响因子：
--
通讯作者：
J. P. M. J. Fuller-J.-P.-M.-J.-Fuller-2298073197;C. B. Gooley;Saper;H P Van Dongen;G. Maislin;J. Mullington;H S Akiskal
中科院分区：
文献类型：
--
作者：
J. P. M. J. Fuller-J.-P.-M.-J.-Fuller-2298073197;C. B. Gooley;Saper;H P Van Dongen;G. Maislin;J. Mullington;H S Akiskal
突变小鼠睡眠稳态的变化为未来的研究工作提供了一个可验证的假设，即为什么具有突变的人类受试者尽管睡眠持续较短，但生活却如此活跃。我们对Dec 2 KO小鼠及其WT同窝仔进行EEG和EMG。基线觉醒、NREM和REM百分比显示，Dec 2 KO小鼠的睡眠略多于WT小鼠，且差异主要在黑暗期（表S4和图S2）。在光照期间，只有Dec 2 KO小鼠的NREM睡眠比WT小鼠的NREM睡眠更丰富，并且仅略微丰富。Dec 2基因敲除小鼠睡眠剥夺后NREM的反弹要慢得多，这意味着Dec 2是调节睡眠恢复的重要因素。我们接下来着手测试mDec 2 P385 R是否可以在果蝇中引起类似的休息-睡眠表型。果蝇中与DEC 2最接近的同源蛋白[CG 17100，发条橙子（16，17）]具有<18%的氨基酸序列相似性，<11%的同一性，并且P385不保守。因此，我们在w1118背景下产生了具有表达诱导型UAS-mDec 2 WT和UAS-mDec 2 P385 R的转基因果蝇。当这些果蝇与驱动泛神经元过表达的elav-GAL 4杂交时（18），与WT果蝇相比，mDec 2 P385 R果蝇显示出显著较低的日间睡眠样行为，具有减少的休息回合次数和延长的休息回合持续时间（图4A）。由于蘑菇体被证明是果蝇中可能的睡眠-休息行为中心（19），我们还在蘑菇体30 Y-GAL 4驱动子的控制下过表达P385 R和WT mDec 2（20）。值得注意的是，由30 Y-GAL 4驱动的mDec 2 P385 R转基因果蝇显示出比mDec 2 WT果蝇显著更少的类睡眠行为，在亮相和暗相两者中具有显著更短的睡眠回合持续时间（图4 B）。然而，休息或睡眠回合数显着更高，只有在黑暗阶段的mDec 2 P385 R转基因苍蝇。这些结果表明，具有mDec 2 P385 R的蘑菇体驱动表达的果蝇的行为与DEC 2-P385 R转基因小鼠的行为相呼应（图2，B、C和E，以及图4 B）。人类遗传学在研究人类行为特征中的力量在FASPS的突变鉴定和随后的分子表征中得到了证明（21-23）。正如目前所了解的，FASPS主要是一种昼夜节律变异，导致相位改变;每日总睡眠时间是正常的（21，23，24）。我们应用了类似的方法并鉴定了一个参与调节睡眠量的基因。这为……提供了一个独特的机会。
changes in sleep homeostasis in the mutant mice provide a testable hypothesis for future work examining why human subjects with the mutation lead such active lives despite their persistently shorter sleep. We performed EEG and EMG on Dec2 KO mice and their WT littermates. Baseline wake-fulness, NREM, and REM percentages showed that Dec2 KO mice sleep slightly more than the WT mice and that the difference is mostly in the dark period (table S4 and fig. S2). During the light period, only the NREM sleep of Dec2 KO mice was more abundant than that of WT mice and only slightly so. NREM rebound after sleep deprivation for Dec2 KO mice was much slower, which implied that Dec2 is an important factor regulating sleep recovery. We next set out to test whether mDec2P385R can cause a similar rest-sleep phenotype in Dro-sophila. The closest homologous protein to DEC2 in Drosophila [CG17100, clockwork orange (16, 17)] shares <18% amino acid sequence similarity , <11% identity, and P385 is not conserved. We therefore generated transgenic flies with expression-inducible UAS-mDec2WT and UAS-mDec2P385R on the w1118 background. When these flies were crossed with elav-GAL4, driving pan-neuronal overexpression (18), mDec2P385R flies showed significantly lower daytime sleep-like behavior with reduced rest bout number and lengthened rest bout durations compared with WT flies (Fig. 4A). Because mushroom bodies were shown to be the likely sleep-rest behavior center in Drosophila (19), we also overexpressed P385R and WT mDec2 under the control of a mushroom body 30Y-GAL4 driver (20). It was noteworthy that mDec2P385R transgenic flies driven by the 30Y-GAL4 showed significantly less sleeplike behavior with significantly shorter sleep bout duration in both light and dark phases than mDec2WT flies (Fig. 4B). However, rest or sleep bout number was significantly higher only in the dark phase for mDec2P385R trans-genic flies. These results indicate that the behavior of flies with mushroom body driver expression of mDec2P385R echoed those of the DEC2-P385R transgenic mice (Fig. 2, B, C, and E, and Fig. 4B). The power of human genetics in studying human behavioral traits was demonstrated in the identification of mutations and the subsequent molecular characterization of FASPS (21–23). As currently understood, FASPS is primarily a circadian rhythm variant leading to altered phase; total daily sleep time is normal (21, 23, 24). We have applied a similar approach and identified a gene involved in regulation of sleep quantity. This provides a unique opportunity for …