SIRNA
siRNA
sRNA与 MiRNA的区别 1)来源不同: miRNAs derive from genomic loci distinct from other recognized genes, whereas siRNAs often derive from mRNAS, transposons, viruses or heterochromatic dna 2)结构不同: miRNAs are processed from transcripts that can form local rNA hairpin structures, whereas siRNAs are processed from long bimolecular RNA duplexes or extended hairpins 3)加工不同: A single miRNA:mRNA* duplex is generated from each miRNA hairpin precursor molecule, whereas a multitude of sirNa duplexes are generated from each siRNA precursor molecule, leading to many different siRNAs accumulating from both strands of this extended dsRNA 4)保守性不同: miRNa sequences are nearly always conserved in related organisms, whereas endogenous siRNa sequences are rarely conserved These types of differences are the basis of practical guidelines for distinguishing and annotating newly discovered miRNAs and endogenous siRNAs
siRNA与miRNA的区别 1）来源不同：miRNAs derive from genomic loci distinct from other recognized genes, whereas siRNAs often derive from mRNAs, transposons, viruses, or heterochromatic DNA 2）结构不同：miRNAs are processed from transcripts that can form local RNA hairpin structures, whereas siRNAs are processed from long bimolecular RNA duplexes or extended hairpins. 3）加工不同：A single miRNA:miRNA* duplex is generated from each miRNA hairpin precursor molecule, whereas a multitude of siRNA duplexes are generated from each siRNA precursor molecule, leading to many different siRNAs accumulating from both strands of this extended dsRNA. 4）保守性不同：miRNA sequences are nearly always conserved in related organisms, whereas endogenous siRNA sequences are rarely conserved. These types of differences are the basis of practical guidelines for distinguishing and annotating newly discovered miRNAs and endogenous siRNAs
SIRNA的种类 D) natural cis-acting RNA--na-ciRNA natural cis- antisense rnac(压力诱导 SiRNA); 3)repeat-associated short interfering RNAs (rasi-RNAS); 4 heterochromatin siRNA-hc sirnA; 5 scan rNa (scn RNa)
siRNA的种类 1) natural cis-acting RNA—na-ciRNA; 2) natural cis-antisense RNA(压力诱导siRNA); 3) repeat-associated short interfering RNAs (rasi-RNAs); 4) heterochromatin siRNA—hc siRNA; 5 scan RNA (scn RNA)
natural cis-acting RNA 源于外源入侵的病毒产生的小分子双链RNA: 1)植物外源入侵的病毒产生的小分子双链RNA; 2)无脊椎动物外源入的侵病毒产生的小分子双链 RNA
natural cis-acting RNA 源于外源入侵的病毒产生的小分子双链RNA： 1）植物外源入侵的病毒产生的小分子双链RNA； 2）无脊椎动物外源入的侵病毒产生的小分子双链 RNA
DCL4 病毒RNA 病毒RNA TTTTTTTTTTTTTTTTT 植物病 病毒复制 毒入侵 病毒RNA TTTT haNl viral RNA-dependeted RNA Polymer 诱导产 HEN1 IMro 生的 21nt vral siRNAs 21nt病毒 SIRNA 初生 RNA解旋 RISC SIRNA 病毒RNA 病毒RNA切割
植物病 毒入侵 诱导产 生的 初生 siRNA
植物病 DNA病毒 感染细胞非感染细胞 Infected cell Non-infected Cell 毒入侵 RNA病毒 RNA virus 诱导产 MMUNIZATION 免疫 7DCL4 扩放 生的 SMD1 Stabilizatio i CH3- 短距离扩散 次生 扩放 Passenger ,. o@降解 RNADNA virus SDE3 transcription SIRNA stational 诱导系统抗性 The figure shows how primary viRNAs (1st) are amplified into secondary viRNAs(2nd)in the RDR6-dependent pathway. Aberrant (ab)viral mRNAs lacking a cap or polya tail (AAA) can enter RNA-dependent RNA polymerase pathways independently of 1st viRNA synthesis. A DCL4-dependent silencing signal (arbitrarily depicted as free 21 nucleotide viRNAs )moves through the plasmodesmata(P)to immunize neighboring cells Movement may be enhanced through further rounds of amplification involving viral transcripts that enter immunized cells. VSRs and potential endogenous silencing suppressors(red ) represent genetic rather than direct physical interactions with host silencing components
植物病 毒入侵 诱导产 生的 次生 siRNA The figure shows how primary viRNAs (1st) are amplified into secondary viRNAs (2nd) in the RDR6-dependent pathway. Aberrant (ab) viral mRNAs lacking a cap or polyA tail (AAA) can enter RNA-dependent RNA polymerase pathways independently of 1st viRNA synthesis. A DCL4-dependent silencing signal (arbitrarily depicted as free 21 nucleotide viRNAs) moves through the plasmodesmata (P) to immunize neighboring cells. Movement may be enhanced through further rounds of amplification involving viral transcripts that enter immunized cells. VSRs and potential endogenous silencing suppressors (red) represent genetic rather than direct physical interactions with host silencing components
Drosophila C elegans 果蝇与线虫病毒入 RNA Virus RNA Virus miRNA 侵诱导产生的 dsRNA SiRNA RDE4 1st=国R AAA AAA (A)The Drosophila pathway is conceptually 60s @ Armi similar to a linear antiviral silencing Pathway in plants (B) Antiviral silencing in C elegans has been AAA AAA AAA inferred through studies of artificial infection systems. ALG, RDE-1, and SAGO are worm Translational repression? Degradation AGOs that recruit miRNAs, 1st siRNAs, and 2nd siRNAs, respectively. RRF-1 is thought to 注:红色代表病毒产生可抑制 produce 2nd siRNAs or to copy RNAS CRNAs) 宿主细胞抗病毒机制的成 2nd cRNA directly from RDE3-stabilized templates. SID-1 分 SAGO-1 may possibly take up viral dsRNAs into cells These pathways can be disrupted at multiple AAA points by endogenous suppressors(red) cel130413-426,2007 De gradation ?
果蝇与线虫病毒入 侵诱导产生的 siRNA (A) The Drosophila pathway is conceptually similar to a linear antiviral silencing Pathway in plants. (B) Antiviral silencing in C. elegans has been inferred through studies of artificial infection systems. ALG, RDE-1, and SAGO are worm AGOs that recruit miRNAs, 1st siRNAs, and 2nd siRNAs, respectively. RRF-1 is thought to produce 2nd siRNAs or to copy RNAs (cRNAs) directly from RDE3-stabilized templates. SID-1 may possibly take up viral dsRNAs into cells. These pathways can be disrupted at multiple points by endogenous suppressors (red). Cell, 130:413-426, 2007
植物sRNA在细胞间的转移 初生25nt SiRNA在细 胞间的转移 距离较近, 10.15 cells 仅在数个 siRNA 细胞之间 次生21nt SiRNA可 在10-15个 SCE3 SCE1 细胞之间转 次级 siRNA 移 P:胞间连丝
植物siRNA在细胞间的转移 初生25nt siRNA在细 胞间的转移 距离较近, 仅在数个 细胞之间. 次生21nt siRNA可 在10-15个 细胞之间转 移
Salt Natural cis Salt stress stress tolerance antisense RNA SRos 1- RoSt+psct- SCD roin Degradation of p5cdh mrNA decreases P5CDH activity and proline degradation. Decreased proline degradation contributes to salt-induced P5CDH proline accumulation and salt tolerance Constitutive induced but at the same time leads to the ros P5CDH mRNAK Accumulation caused by buildup of the SRO5 mi P5CDH proline catabolic intermediate P5C. This mRNA ROS accumulation is potentially harmful but is also a signal to initiate further DCL2 24-nt nat-siRNA 曹 formation and stress responses. The Sro5 protein initial cleavage SGS3 RISC counteracts P5C-induced ROS SDE4 accumulation, thus completing a dsRNA and regulatory loop that allows fine tuning of 21-nt nat-siRNA DCL1 formation ROS accumulation and stress response
Natural cisantisense RNA Degradation of P5CDH mRNA decreases P5CDH activity and proline degradation. Decreased proline degradation contributes to salt-induced proline accumulation and salt tolerance but, at the same time, leads to the ROS Accumulation caused by buildup of the proline catabolic intermediate P5C. This ROS accumulation is potentially harmful but is also a signal to initiate further stress responses. The SRO5 protein counteracts P5C-induced ROS accumulation, thus completing a regulatory loop that allows fine tuning of ROS accumulation and stress response
植物 反向重叠互补转录产物 na-siRNA OliVA RDRE SGS DRB? DCL 的加工 HEN1 Ⅲm24 nt nat- siRNA双链 na- SiRNA即 natural 5^na- SiRNA前体 cis- acting siRNA产 24nt nat-siRNA 生于内源的cis SGS3 RR》拷贝复制 antisense基因的表 达产物.两步生成: DRB? DCL1 HEN1 24nt na-siRNA 21 nt nat-siRNA,双链 21nt na-SiRNA J 在拟南芥盐诱导压 GO? na_ sirNA前体 21nt nat-siRNA 力环境下产生.作 用于自身mRNA mRNA降解
植物 na-siRNA 的加工 na-siRNA即natural cis-acting siRNA.产 生于内源的cisantisense 基因的表 达产物. 两步生成: 24nt na-siRNA→ 21nt na-siRNA. 在拟南芥盐诱导压 力环境下产生. 作 用于自身mRNA
