低等植物蓝光受体信号传导研究

拟南芥含有5个已分离的蓝光受体和至少1个未鉴定的蓝光/紫外光-A受体.隐花色素(CRY1、CRY2和CRY3) 调节植物的形态建成、开花和生物节律性,而向光素 (PHOT1和PHOT2) 调节植物的向光性、叶绿体运动和气孔开放.黄素可以吸收蓝光和紫外光-A,是CRY和PHOT蓝光受体的生色团.对这些光受体的结构和作用模式已了解很多.苔藓植物小立碗藓中含有2个已分离的隐花色素(CRY1a和CRY1b),负责调节侧枝形成和调控生长素反应;有4个向光素(PHOTA1,PHOTA2,PHOTB1,PHOTB2) 调节叶绿体的运动.苔藓细胞内蓝光/紫外光-A引发的信号转导有Ca2+参与.     

植物蓝光受体研究进展

植物蓝光调节的反应主要有向光性、抑制幼茎伸长、叶绿体迁移、刺激气孔张开和调节基因表达等。蓝光反应的有效波长是蓝光和近紫外光(320—400am),故蓝光受体也叫蓝光／近紫外光受体。植物蓝光受体研究近年来取得较大进展。以拟南芥为例,已得到确认的受体至少有隐花色素(CRY1、2)和向光蛋白(phototropin)两大类。转基因拟南芥对蓝光、紫外光和绿光敏感,并发现CRY1是一个可溶性蛋白。CRY2编码一个核蛋白,蓝光在转录水平对该蛋白进行调节,它的作用是增加拟南芥对蓝光的敏感性。CRY1和CRY2共同介导了拟南芥植物的向光性。隐花色素的蛋白与辅基之间以非共价键连接,可以吸收蓝光和近紫外光。CRY1和CRY2蛋白之间,尤其是N端相似性很高。向光蛋白目前只发现PHOT1和PHO12两种,向光蛋白作为丝／苏氨酸激酶蓝光受体含有两个光氧化结构域(LOV)并参与了植物向光性叶绿体运动、气孔开放等。     

植物蓝光反应突变体分子生物学研究

植物具备一套复杂的由3种蓝光受体和多种信号转导下游组分组成的蓝光感应系统,通过感受光照强度、光的方向和光周期,调节自身对蓝光的应答.本文综述了植物蓝光反应突变体分子生物学研究进展,探讨蓝光受体及信号转导下游组分在植物发育中的作用及蓝光诱发植物作出反应的分子机制.     

苔藓植物蓝光/紫外光-A 信号传导的研究

种子植物含有5个已分离的光受体和至少1个未鉴定的蓝光/紫外光-A受体。隐花色素(CRY1、CRY2和CRY3) 调节植物的生长发育,而向光蛋白(PHOT1和PHOT2) 调节植物对光的营养反应。黄素可以吸收蓝光和紫外光-A,是生色团。对这些光受体的结构和作用模式已了解很多。苔藓植物小立碗藓中含有2个已分离的隐花色素(CRY1a和CRY1b),负责调节侧枝形成和生长素代谢;有4个向光蛋白(PHOTA1,PHOTA2,PHOTB1,PHOTB2) 调节叶绿体的运动。苔藓细胞内蓝光/紫外光-A刺激引发的信号转导有Ca2+参与。     

植物蓝光反应突变体分子生物学研究

植物具备一套复杂的由3种蓝光受体和多种信号转导下游组分组成的蓝光感应系统,通过感受光照强度、光的方向和光周期,调节自身对蓝光的应答。本文综述了植物蓝光反应突变体分子生物学研究进展,探讨蓝光受体及信号转导下游组分在植物发育中的作用及蓝光诱发植物作出反应的分子机制。     

《当代生物学》：拟南芥蓝光受体反应研究获进展

近日来自湖南大学、中国农业科学研究所和加州大学的研究人员在新研究中对拟南芥蓝光受体CRY2及信号介导下游组分在植物发育中的作用及蓝光诱发植物做出反应的分子机制进行了探讨,相关研究论文于4月21日发表在著名期刊《细胞》（Cell）旗下的子刊《当代生物学》（Current Biology）杂志上。     

蓝光、紫外光的受体及其对CHS表达诱导的研究

植物在进化过程中形成了对环境信号反应的能力,光是植物生长发育中的一个重要的环境信号。综述了蓝光、紫外光的受体及蓝光、紫外光对编码植物类黄酮合成中的一个重要的限速酶——苯基苯乙烯酮合酶基因CHS的诱导作用,并介绍该反应信号转导的可能组分。     

蓝光、紫外光的受体及其对CHS表达诱导的研究

植物在进化过程中形成了对环境信号反应的能力,光是植物生长发育中的一个重要的环境信号,综述了蓝光,紫外光的受体及蓝光,紫外光对编码植物类黄酮合成中的一个重要的限速酶－苯基苯乙烯酮合酶基因CHS的诱导作用,并介绍该反应信号转导的可能组分。     

蓝光受体下游信号转导组分的研究进展

为了全面了解蓝光受体信号转导组分及其调节机制的研究进展,着重地阐述了蓝光受体的信号转导组分中的Ca~(2 )、蛋白质的可逆磷酸化、阴离子通道和G蛋白,以及植物如何通过多条信号转导途径调节其形态和发育的变化以适应环境的变化等。     

植物下胚轴向光弯曲机制研究进展

植物向光弯曲生长主要是由于其向光和背光面生长素的不对称分布引起。近年来研究发现,在不同强度的蓝光单侧照射下,植物可能存在不同的向光弯曲调节机制。目前,关于向光素PHOT1介导弱蓝光引起的下胚轴弯曲研究较为详细,即PHOT1感受蓝光后,与其下游的信号蛋白NPH3、RPT2和PKS1相互作用,调控生长素运输蛋白的活性及定位,诱导生长素的不对称分布引起向光弯曲。PHOT1和PHOT2以功能冗余方式调节强蓝光引起的植物下胚轴向光弯曲,NPH3可能作为共享调节因子,引发不同的信号转导通路实现功能互补。此外,其他光受体、激素、蛋白激酶、蛋白磷酸酶以及Ca2＋也参与了植物向光弯曲的调节。本文就近年来有关植物下胚轴向光弯曲信号组分及可能的网络关系进行总结,并对该研究领域存在的问题及今后可能的研究方向进行展望。     

蓝光受体CRY1和CRY2对拟南芥钾吸收影响的研究

以拟南芥野生型Col-4和蓝光受体突变体cry1,cry2和cry1cry2为材料在蓝光下进行缺K+处理,cry1cry2的下胚轴及根的伸长受抑制程度最大.经过对K+充足条件下的Col-4,cry1,cry2和cry1cry2的钾元素含量和持水性检测.以及采用定量PCR对K+转运栽体和离子通道相关基因如AKT1,AtKC1,AKUP1等表达水平的分析,发现cry1cry2的钾元素含量最高、持水性最低,且其K+转运载体和离子通道相关基因的表达量也最高.该结果说明蓝光下CRY1和CRY2的缺失对K+的吸收起促进作用.     

Quantitative real-time kinetics of optogenetic proteins CRY2 and CIB1/N using single-molecule tools

In this work we evaluate the interaction of two optogenetic protein variants (CIB1, CIBN) with their complementary protein CRY2 by single-molecule tools in cell-free extracts. After validating the blue light induced co-localization of CRY2 and CIB1/N by Förster resonance energy transfer (FRET) in live cells, a fluorescence correlation spectroscopy (FCS) based method was developed to quantitatively determine the in vitro association of the extracted proteins. Our experiments suggest that CIB1, in comparison with CIBN, possesses a better coupling efficiency with CRY2 due to its intact protein structure and lower diffusion rate within 300 s detection window.     

拟南芥光形态突变体的筛选与基因鉴定

以哥伦比亚(Columbia)野生型拟南芥(Arabidopsis thaliana)为实验材料,用含有激活标记双元质粒pCB260的农杆菌浸花进行转化,构建拟南芥T-DNA插入突变体库.通过突变体的筛选和表型分析,获得了两株光形态突变体,子叶下胚轴伸长的光抑制效应减弱.通过TAIL-PCR(thermal asymmetric interlaced-PCR)技术,成功扩增出突变植株T-DNA插入位点侧翼序列,经NCBI序列比对,T-DNA分别插在CRY1第一和第三外显子部位.突变体的表型分析及PCR鉴定结果表明,T-DNA插入CRY1并影响到突变植株的光形态建成.     

拟南芥转录因子HB22与CRY1相互作用研究

通过酵母双杂交的方法,从拟南芥转录因子库中筛选出了6个与CRY1相互作用的转录因子.为了测定其中的HB22与CRY1相互作用的强度,采用了ONPG与CPRG两种方法对其β-半乳糖苷酶活性进行了分析.结果显示在蓝光光强为50μmol/m2s,孵育时间为4 h的情况下,蓝光与暗处理情况下的β-半乳糖苷酶活性比值分别为1.668和2.18.进一步设置蓝光处理时间及光强梯度实验数据显示,在蓝光光强为50μmol/m2s孵育时间为3 h时,二者相互作用强度达到最高.说明HB22与CRY1的相互作用具有蓝光响应.对蓝光处理不同时间的野生型col-4与cry1缺失突变体的材料进行HB22基因的定量PCR分析,发现拟南芥cry1缺失突变体中该基因的表达量比野生型中高,在蓝光处理2 h时,缺失突变体中表达量为野生型中的6倍左右.说明CRY1可能介导蓝光抑制HB22基因表达.     

Clock Genes Display Rhythmic Expression in Human Hearts

Thus far, clock genes in the heart have been described only in rodents, and alterations of these genes have been associated with various myocardial malfunctions. In this study, we analyzed the expression of clock genes in human hearts. Left papillary muscles of 16 patients with coronary heart disease, 39 subjects with cardiomyopathy, and 9 healthy donors (52 males and 12 females, mean age 55.7±11.2; 16–70 yrs) were obtained during orthotopic heart transplantation. We assessed the mRNA levels of PER1, PER2, BMAL1, and CRY1 by real time PCR and analyzed their rhythmic expression by sliding means and Cosinor functions. Furthermore, we sought for differences between the three groups (by ANOVAs) for both the total 24 h period and separate time bins. All four clock genes were expressed in human hearts. The acrophases (circadian rhythm peak time) of the PER mRNAs occurred in the morning (PER1: 07:44 h [peak level 187% higher than trough, p?=?.008]; PER2: 09:42 h [peak 254% higher than trough, p?<?.0001], and BMAL1 mRNA in the evening at 21:44 h [peak 438% higher than trough; p?<?.0001]. No differences were found in the rhythmic patterns between the three groups. No circadian rhythm was detected in CRY1 mRNA in any group. PER1, PER2, and BMAL1 mRNAs revealed clear circadian rhythms in the human heart, with their staging being in antiphase to those in rodents. The circadian amplitudes of the mRNA clock gene levels in heart tissue are more distinct than in any other human tissue so far investigated. The acrophase of the myocardial PER mRNAs and the trough of the myocardial BMAL1 coincide to the time of day of most frequent myocardial incidents.     

Opto-vTrap,an optogenetic trap for reversible inhibition of vesicular release,synaptic transmission,and behavior

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Haloperidol,but not olanzapine,may affect expression of PER1 and CRY1 genes in human glioblastoma cell line

Background: There is barely any evidence of antipsychotic drugs affecting the molecular clockwork in human, yet it is suggested that clock genes are associated with dopaminergic transmission, i.e. the main target of this therapeutics. We decided to verify if haloperidol and olanzapine affect expression of CLOCK, BMAL1, PER1 and CRY1 in a human central nervous system cell line model. Methods: U-87MG human glioblastoma cell line was used as an experimental model. The cells were incubated with or without haloperidol and olanzapine in the concentration of 5 and 20 μM for 24 h. Real-time quantitative polymerase chain reaction with the ΔC_T analysis was used to examine the effect of haloperidol and olanzapine on the mRNA expression of the genes. Results: At 5 μM, haloperidol decreased expression of CRY1 almost 20-fold. There was nearly a 1.5-fold increase in expression of PER1. Considering the 20 μM haloperidol concentration and both olanzapine concentrations, no other statistically significant effect was observed. Conclusions: At certain concentration, haloperidol seems to affect expression of particular clock genes in a human central nervous system cell line model, yet mechanism underlying this phenomenon remains elusive.     

Pleiotropic effects of the Arabidopsis cryptochrome 2 allelic variation underlie fruit trait-related QTL

The previous molecular identification of a flowering time QTL segregating in the Arabidopsis L er x Cvi cross, demonstrated that natural allelic variation at the blue light photoreceptor CRY2 gene affects flowering time (El-Assal et al., 2001). In addition, previous works on the same cross have mapped several QTL affecting other unrelated life history traits in the CRY2 genomic region. In the present report, we have used a set of Arabidopsis L er transgenic plants carrying four different functional CRY2 transgenes for phenotypic analyses, with the aim of exploring the extent of pleiotropy of CRY2 allelic variation. It is concluded that previously identified QTL affecting fruit length, ovule number per fruit, and percentage of unfertilized ovules are caused by this same Ler/Cvi CRY2 allelic variation. In addition, dose effects of the CRY2-L er allele are detected for fruit length. A seed weight QTL at the map position of CRY2 could not be confirmed and also no effect on seed dormancy was observed. Thus, it is shown that transgenic plants carrying different alleles can be a useful tool to attribute QTL for different complex traits to a specific locus, even when the relationship among the traits has not been previously suggested.