基于CRISPR/Cas9技术构建TRPV1基因敲除的CACO-2稳定细胞系

基于CRISPR/Cas9基因编辑技术敲除人结直肠腺癌细胞Caco-2中的辣椒素受体基因TRPV1,构建TRPV1基因敲除的Caco-2稳定细胞系.使用CRISPR/Cas9在线靶点设计程序在TRPV1基因4个转录本的公共CDS区的第一个外显子DNA区域中设计一对gRNA,将gRNA构建到真核重组表达质粒的载体上,电转染待敲除细胞,经嘌呤毒素抗性筛选和基因测序获得敲除TRPV1基因的稳定细胞系.用Western Blot检测TRPV1基因蛋白表达量验证Caco-2中TRPV1基因的敲除效果,CCK-8检测TRPV1基因敲除细胞的生长曲线,与野生型细胞对比检测TRPV1基因敲除对细胞生长的影响.筛选出TRPV1基因敲除的CACO-2稳定细胞系,而且TRPV1基因敲除对Caco-2细胞生长无显著影响.基于CRISPR/Cas9基因编辑技术成功构建了TRPV1基因敲除的CACO-2稳定细胞系,为后续研究辣椒素对肠道脂类吸收影响的机理研究提供了有利的工具.     

原代小鼠卵巢上皮细胞TP53基因敲除及其生物学特征变化

目的 利用CRISPR/Cas9慢病毒载体系统建立小鼠原代卵巢上皮细胞TP53基因稳定敲除细胞系,分析细胞增殖、细胞周期、克隆形成以及细胞转移侵袭能力的变化。方法 构建LentiCRISPRv2-sgRNA TP53基因敲除质粒,用293FT细胞进行慢病毒包装,转导小鼠原代卵巢上皮细胞,嘌呤霉素筛选出稳定敲除细胞系,进行PCR、蛋白免疫印迹以及免疫荧光鉴定。细胞增殖、细胞周期变化、克隆形成、细胞迁移侵袭能力分别用MTT、流式细胞分析、单层培养以及Transwell小室进行测定。结果 TP53基因敲除小鼠原代卵巢上皮细胞中P53表达缺失;TP53敲除引起细胞迅速增殖,DNA合成加速,克隆形成以及迁移侵袭能力增强。结论 获得了原代小鼠卵巢上皮细胞TP53基因稳定敲除细胞系,细胞生物学特征明显改变。     

泛素连接酶E6AP敲减及过表达稳转细胞株的构建与鉴定

目的旨在筛选出能稳定敲减及过表达泛素连接酶E6AP的细胞株,在这两种情况下比较已知底物Arc的泛素化修饰区别,以期进一步阐明E6AP通过调控底物的泛素化进而影响底物下游功能的机理。方法从人胚肾293细胞中提取RNA再反转录成cDNA,以c DNA为模板通过PCR扩增得到E6AP目的条带,将E6AP基因克隆至p LVXIRES-mCherry质粒,构建过表达质粒;同时,合成可特异性结合E6AP mRNA的shRNA,并克隆至GIPZ质粒,构建敲减质粒。结果通过嘌呤霉素筛选得到敲减及过表达稳转细胞株,通过免疫共沉淀实验比较底物的泛素化修饰区别。结论成功构建E6AP敲减及过表达稳转细胞株,并能相应影响HEK-293细胞中底物Arc的泛素化修饰水平。     

利用CRISPR/Cas9方法敲除CBFβ基因及CBFβ真核表达载体的构建

构建CBFβ敲除Hep G2细胞系及CBFβ真核表达载体。CRISPR/Cas9基因敲除,将表达CBFβsgRNA,Cas9的表达载体共转Hep G2细胞,嘌呤霉素筛选基因敲除细胞,构建细胞系。infusion cloning方法构建CBFβ表达载体,Hep G2细胞提取RNA,反转成c DNA,设计CBFβ引物扩增目的基因,连接,转化,挑取阳性克隆,PCR鉴定,酶切鉴定,测序进一步鉴定。获得了稳定敲除CBFβ的Hep G2细胞系及在Hep G2细胞中稳定表达的CBFβ真核表达载体。为研究CBFβ基因在对乙型肝炎病毒复制的调控及调控机制奠定了基础。     

基于CRISPR/Cas9系统构建Slfn2基因敲除的小鼠肺癌细胞系

为构建Slfn2^-/-小鼠肺癌细胞系(Lewis lung carcinoma, LLC),本文利用CRISPR/Cas9技术,在CHOPCHOP网站筛选Slfn2基因的sgRNA序列,将合成的oligo序列退火后连接至pLenti CRISPR v2质粒中,并与pMD2.G、psPAX2共转染至293T细胞中包装慢病毒;利用包装的慢病毒感染LLC细胞,经筛选和单克隆培养,获取Slfn2^-/-敲除的LLC细胞。结果显示：SgRNA成功插入载体重组质粒;利用3质粒包装的慢病毒成功将LLC中的Slfn2基因突变,获得丢失8个碱基移码突变和丢失180个碱基缺失突变的Slfn2^-/-小鼠肺癌细胞。可见,利用CRISPR/Cas9技术成功构建了Slfn2基因敲除的小鼠肺癌细胞。     

番茄SlSL1重组蛋白的表达、纯化及体外泛素化活性检测

泛素化作为真核生物细胞内普遍存在且极为关键的蛋白质翻译后修饰,可以使被修饰的蛋白质发生降解,在植物生长发育、胁迫应答等方面发挥着重要作用。泛素化降解需要通过E3泛素连接酶特异性识别靶蛋白并对其进行修饰,因此E3连接酶在泛素化途径中起着决定性的作用。文章通过克隆番茄SlSL1基因编码序列、构建原核重组表达质粒,并利用诱导表达、亲和吸附纯化SlSL1重组蛋白,以此进行SlSL1的体外泛素化活性检测。SDS-PAGE电泳和考马斯亮蓝染色结果显示,由所构建番茄SlSL1基因重组质粒纯化获得SlSL1蛋白;体外泛素化检测显示,SlSL1蛋白形成多聚化泛素条带,具有E3泛素连接酶活性,表明SlSL1可能在番茄的泛素化调控途径中发挥功能。     

利用CRISPR/Cas9技术构建GLRX3基因敲除的HEK293细胞系

为了构建GLRX3(Glutaredoxin 3)敲除的HEK293细胞系,根据该蛋白结构特性设计了靶向于GLRX3基因Exon5的4个sgRNA,并通过T7E1检测确认了所设计sgRNA的有效性。将携带Cas9及靶向hGLRX3-Exon5的sgRNA1的打靶载体转染HEK293,通过药物Puromycin和细胞克隆化筛选出稳定GLRX3基因敲除的HEK293细胞株,并通过测序确定GLRX3两个等位基因均发生移码突变。通过免疫印迹在蛋白表达水平确认了该基因的敲除。利用CRISPR/Cas9技术成功构建了GLRX3敲除的HEK293细胞株,其为探索GLRX3的功能和作用机制提供了有效的细胞模型。     

转录组和蛋白质组整合分析揭示组蛋白H2A去泛素化酶USP16的功能调控网络

作为主要的H2AK119ub去泛素化酶,USP16与造血功能异常、神经发育、癌症发生等病理过程密切相关。它能够调控染色质的动态性和可及性进而调控转录,也调控细胞周期。尽管USP16在细胞核内发挥功能,但它主要定位于细胞质中。迄今对USP16下游具体的功能网络和信号途径缺乏深入研究。在本研究中,我们通过对来自HeLa细胞和两株usp16稳定敲低细胞系的转录组和蛋白质组数据进行对比整合分析,发现usp16敲低后上调的基因和蛋白主要与细胞骨架形成、细胞形态构建等相关的生物学过程有关,usp16敲低后下调的基因和蛋白与线粒体中的蛋白翻译和代谢过程有关。     

CRISPR/Cas9基因转录激活技术的建立及其应用

建立基于CRISPR/Cas9的基因转录激活技术,实现在HEK293细胞中激活cGAS基因的转录。首先利用慢病毒载体构建稳定表达Cas9的HEK293细胞;并采用Real-time PCR和western blot方法鉴定Cas9蛋白质表达效果。再选取不同靶序列,分别构建用于激活cGAS基因转录的sgRNA载体,将构建好的序列载体与CRISPR体系工具质粒共转染至稳定表达Cas9的HEK293细胞中。采用Real-time PCR方法检测细胞中内源cGAS的转录激活效果。成功建立了基于CRISPR/Cas9的基因转录激活技术,并在c GAS基因阴性表达的细胞中激活基因的转录。     

CRISPR/Cas9系统介导的斑马鱼park2基因的定点敲除

作为目前最新、最先进的基因编辑技术,CRISPR/Cas9系统为分子细胞生物学带来革命性发展,以它的简单高效、灵活性以及可实现DNA序列的定向突变而被广泛使用.斑马鱼的park2基因位于第13号染色体上,编码的Parkin蛋白是一个E3泛素连接酶.该基因在斑马鱼中的功能还不清楚.利用CRISPR/Cas9系统,首次在斑马鱼胚胎中实现了park2基因的大片段删除.由于斑马鱼在发育和疾病研究中有很大优势,实现park2基因敲除将有助于将来进一步研究该基因的功能.     

SHARPIN forms a linear ubiquitin ligase complex regulating NF-κB activity and apoptosis

SHARPIN is a ubiquitin-binding and ubiquitin-like-domain-containing protein which, when mutated in mice, results in immune system disorders and multi-organ inflammation. Here we report that SHARPIN functions as a novel component of the linear ubiquitin chain assembly complex (LUBAC) and that the absence of SHARPIN causes dysregulation of NF-κB and apoptotic signalling pathways, explaining the severe phenotypes displayed by chronic proliferative dermatitis (cpdm) in SHARPIN-deficient mice. Upon binding to the LUBAC subunit HOIP (also known as RNF31), SHARPIN stimulates the formation of linear ubiquitin chains in vitro and in vivo. Coexpression of SHARPIN and HOIP promotes linear ubiquitination of NEMO (also known as IKBKG), an adaptor of the IκB kinases (IKKs) and subsequent activation of NF-κB signalling, whereas SHARPIN deficiency in mice causes an impaired activation of the IKK complex and NF-κB in B cells, macrophages and mouse embryonic fibroblasts (MEFs). This effect is further enhanced upon concurrent downregulation of HOIL-1L (also known as RBCK1), another HOIP-binding component of LUBAC. In addition, SHARPIN deficiency leads to rapid cell death upon tumour-necrosis factor α (TNF-α) stimulation via FADD- and caspase-8-dependent pathways. SHARPIN thus activates NF-κB and inhibits apoptosis via distinct pathways in vivo.     

SHARPIN is a component of the NF-κB-activating linear ubiquitin chain assembly complex

Cpdm (chronic proliferative dermatitis) mice develop chronic dermatitis and an immunodeficiency with increased serum IgM, symptoms that resemble those of patients with X-linked hyper-IgM syndrome and hypohydrotic ectodermal dysplasia (XHM-ED), which is caused by mutations in NEMO (NF-κB essential modulator; also known as IKBKG). Spontaneous null mutations in the Sharpin (SHANK-associated RH domain interacting protein in postsynaptic density) gene are responsible for the cpdm phenotype in mice. SHARPIN shows significant similarity to HOIL-1L (also known as RBCK1), a component of linear ubiquitin chain assembly complex (LUBAC), which induces NF-κB activation through conjugation of linear polyubiquitin chains to NEMO. Here, we identify SHARPIN as an additional component of LUBAC. SHARPIN-containing complexes can linearly ubiquitinate NEMO and activated NF-κB. Thus, we re-define LUBAC as a complex containing SHARPIN, HOIL-1L, and HOIP (also known as RNF31). Deletion of SHARPIN drastically reduced the amount of LUBAC, which resulted in attenuated TNF-α- and CD40-mediated activation of NF-κB in mouse embryonic fibroblasts (MEFs) or B cells from cpdm mice. Considering the pleomorphic phenotype of cpdm mice, these results confirm the predicted role of LUBAC-mediated linear polyubiquitination in NF-κB activation induced by various stimuli, and strongly suggest the involvement of LUBAC-induced NF-κB activation in various disorders.     

Linear ubiquitination prevents inflammation and regulates immune signalling

Members of the tumour necrosis factor (TNF) receptor superfamily have important functions in immunity and inflammation. Recently linear ubiquitin chains assembled by a complex containing HOIL-1 and HOIP (also known as RBCK1 and RNF31, respectively) were implicated in TNF signalling, yet their relevance in vivo remained uncertain. Here we identify SHARPIN as a third component of the linear ubiquitin chain assembly complex, recruited to the CD40 and TNF receptor signalling complexes together with its other constituents, HOIL-1 and HOIP. Mass spectrometry of TNF signalling complexes revealed RIP1 (also known as RIPK1) and NEMO (also known as IKKγ or IKBKG) to be linearly ubiquitinated. Mutation of the Sharpin gene (Sharpin(cpdm/cpdm)) causes chronic proliferative dermatitis (cpdm) characterized by inflammatory skin lesions and defective lymphoid organogenesis. Gene induction by TNF, CD40 ligand and interleukin-1β was attenuated in cpdm-derived cells which were rendered sensitive to TNF-induced death. Importantly, Tnf gene deficiency prevented skin lesions in cpdm mice. We conclude that by enabling linear ubiquitination in the TNF receptor signalling complex, SHARPIN interferes with TNF-induced cell death and, thereby, prevents inflammation. Our results provide evidence for the relevance of linear ubiquitination in vivo in preventing inflammation and regulating immune signalling.     

结核分枝杆菌Ag85B-ESAT6融合蛋白稳定表达细胞系的建立

建立了能够稳定表达结核分枝杆菌Ag85B-ESAT6融合蛋白的P815细胞系。将Ag85B和ESAT6基因分别克隆至真核表达载体pcDNA3,构建了Ag85B—ESAT6融合蛋白的真核表达质粒Ag85B-pcDNA3-ESAT6。在阳离子聚合物作用下,重组质粒转染与BALB／c遗传背景一致的P815（H-2^4）细胞。通过G418压力筛选后,得到1株阳性克隆细胞。经过RT-PCR检测到该细胞中有Ag85B-ESAT6融合蛋白mRNA表达,用间接免疫荧光可以在转染重组质粒的P815细胞膜上检测到较强的绿色荧光,证实P815细胞内有融合蛋白的表达。获得表达Ag85B-ESAT6融合蛋白的稳定细胞系。     

泛素与EB病毒核抗原1的融合表达载体的构建及表达

成功构建了EB病毒核抗原1(EBNA1)氨基端融合有泛素(ub iqu itin,Ub)的真核表达质粒pC I-Ub-EBNA1。间接免疫荧光分析表明,该重组质粒瞬时转染HeLa细胞后能有效表达。     

反义PARP基因真核表达重组体的构建及其HeLa转化细胞系的建立

利用DNA体外重组技术将PARP基因cDNA部分序列反向克隆到真核表达载体pMAMneo上,构建成重组质粒pMAMneo－C1．4和pMAMneo－C0．3．将重组质粒pMAM－neo－C1．4转染HeLa细胞,经G418筛选,建成细胞系HeLa－C1．4－neo,Southern杂交结果表明,外源PARP基因cDNA部分序列已稳定整合到受体细胞基因组中,该细胞系的建立为研究聚ADP核糖基化作用在细胞内的功能打下了基础．     

人突变型CDK2(F80A)稳定细胞系的建立

将CDK2激酶第80位的Phe突变成Ala,使该激酶特异地利用ATP类似物N6-(2-苯乙基)-ATP(PE-ATP)筛选CDK2激酶的体内特异性底物.将pCMV-CDK2(F80A)-myc载体转染人宫颈癌细胞(HeLa),经持续G418选择和克隆化获得6株抗G418细胞系.Immunoblotting分析发现,挑选的6株细胞系中有4株表达带有myc标签的人突变CDK2蛋白质,其中2株表达量较高,可以作为筛选CDK2底物的细胞系。