Difference between revisions of "Methytransferases and RNAi Pathways"
(→DNA methyltransferase) |
(→DNA methyltransferase) |
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<ul> | <ul> | ||
<li>MET1 DNA methyltransferase</li> | <li>MET1 DNA methyltransferase</li> | ||
| − | MET1 is responsible for maintaining CG methylation | + | MET1 is responsible for maintaining CG methylation. |
<li>DRM1 and DRM2 DNA methyltransferase</li> | <li>DRM1 and DRM2 DNA methyltransferase</li> | ||
DRM2 is the primary enzyme implicated in the RNAi mediated methylation pathway. Other The enzyme constantly targets CHH sites [http://www.ncbi.nlm.nih.gov/pubmed/19384058 (Widman <i>et. al</i>, 2009)]. DRM2 is expressed at higher levels than DRM1 and is the main enzyme involved in <i>de novo</i> methylation [http://books.google.com/books?id=aBlXT_Y7JCwC&pg=PA3&lpg=PA3&dq=drm1+methylation&source=bl&ots=Cy4nSsNyPE&sig=ei_5_6t6j9cLBObpxE7coRyO1OI&hl=en&ei=5vlHTcagB4XVgQet56WfBg&sa=X&oi=book_result&ct=result&resnum=6&sqi=2&ved=0CDkQ6AEwBQ#v=onepage&q=drm1%20methylation&f=false (Meyer, 2005)]. | DRM2 is the primary enzyme implicated in the RNAi mediated methylation pathway. Other The enzyme constantly targets CHH sites [http://www.ncbi.nlm.nih.gov/pubmed/19384058 (Widman <i>et. al</i>, 2009)]. DRM2 is expressed at higher levels than DRM1 and is the main enzyme involved in <i>de novo</i> methylation [http://books.google.com/books?id=aBlXT_Y7JCwC&pg=PA3&lpg=PA3&dq=drm1+methylation&source=bl&ots=Cy4nSsNyPE&sig=ei_5_6t6j9cLBObpxE7coRyO1OI&hl=en&ei=5vlHTcagB4XVgQet56WfBg&sa=X&oi=book_result&ct=result&resnum=6&sqi=2&ved=0CDkQ6AEwBQ#v=onepage&q=drm1%20methylation&f=false (Meyer, 2005)]. | ||
<li>DRM3 DNA methytransferase</li> | <li>DRM3 DNA methytransferase</li> | ||
| − | [http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1001182;jsessionid=35538162FE4C85BD00D0578063186ED0.ambra01 Henderson <i>et. al</i> (2006)] discovered that DRM3 is required for non-CG DNA methylation. | + | [http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1001182;jsessionid=35538162FE4C85BD00D0578063186ED0.ambra01 Henderson <i>et. al</i> (2006)] discovered that DRM3 is required for non-CG DNA methylation. DRM3 is a catalytically mutated paralog of DRM2. The activity of DRM2 is dependent on DRM3 and a UBA binding domain [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2965745/ (Henderson <i>et. al</i>, 2010)]. Henderson <i>et. al</i> (2006) tested two T-DNA insertion strains (drm3-1 and drm3-2), finding a reduction of methylation of MEA-ISR. After performing a southern blot on the Msp1 (methyl-sensitive restriction enzyme) digested MEA-ISR repeat and sequencing samples of this DNA using the bisulfite method, the researchers concluded that DRM3 is necessary for proper DRM2 functioning. |
<br> | <br> | ||
[[Image:DRM3figure.png]] | [[Image:DRM3figure.png]] | ||
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</UL> | </UL> | ||
---- | ---- | ||
| + | |||
| + | == Other proteins involved in RNAi and chromatin == | ||
| + | NUCLEAR RNA POLYMERASE D1 (NRPD1) | ||
| + | NUCLEAR RNA POLYMERASE E1 (NRPE1) | ||
| + | RNA DEPENDENT RNA POLYMERASE2 (RDR2) | ||
| + | DICER-LIKE3 (DCL3) | ||
| + | ARGONAUTE4 (AGO4) | ||
| + | DEFECTIVE IN RNA DIRECTED DNA METHYLATION 1 (DRD1) | ||
| + | DEFECTIVE IN MERISTEM SILENCING1 (DMS1) | ||
| + | INVOLVED IN DE NOVO 2 (IND2) | ||
| + | SUPPRESSOR OF VARIEGATION 3-9 HOMOLOGUE 2 (SUVH2) | ||
| + | SUPPRESSOR OF VARIEGATION 3-9 HOMOLOGUE 9 (SUVH9) | ||
| + | [http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1001182;jsessionid=35538162FE4C85BD00D0578063186ED0.ambra01 (Henderson <i>et. al</i>, 2006)] | ||
Revision as of 12:50, 1 February 2011
DNA methyltransferase
- MET1 DNA methyltransferase
- DRM1 and DRM2 DNA methyltransferase
- DRM3 DNA methytransferase
MET1 is responsible for maintaining CG methylation.
DRM2 is the primary enzyme implicated in the RNAi mediated methylation pathway. Other The enzyme constantly targets CHH sites (Widman et. al, 2009). DRM2 is expressed at higher levels than DRM1 and is the main enzyme involved in de novo methylation (Meyer, 2005).
Henderson et. al (2006) discovered that DRM3 is required for non-CG DNA methylation. DRM3 is a catalytically mutated paralog of DRM2. The activity of DRM2 is dependent on DRM3 and a UBA binding domain (Henderson et. al, 2010). Henderson et. al (2006) tested two T-DNA insertion strains (drm3-1 and drm3-2), finding a reduction of methylation of MEA-ISR. After performing a southern blot on the Msp1 (methyl-sensitive restriction enzyme) digested MEA-ISR repeat and sequencing samples of this DNA using the bisulfite method, the researchers concluded that DRM3 is necessary for proper DRM2 functioning.
(A) Southern blots hybridized for the MEA-ISR repeat using DNA digested with the methyl-sensitive restriction enzyme MspI. The 4.3 kb band and 2 kb bands represent digested and undigested DNA respectively. (B) Graphical representation of bisulfite sequencing at MEA-ISR with % cytosine methylation shown for each genotype. CG sequence contexts are shaded black, CHG are shaded grey and white represents CHH. The 95% confidence limits shown are given by the Wilson score interval. (C) Graphical representation of bisulfite sequencing at the methylated promoter repeats of the FWA endogene with % cytosine methylation shown for each genotype and shaded according to sequence context as in (B). (D) Quantitative PCR measurement of AtSN1 genomic DNA following restriction endonuclease digestion with DNA methylation sensitive enzyme HaeIII. The value on the y-axis represents the ratio of DNA measured by quantitative PCR with and without HaeIII digestion. The data represents three biological replicates and the error bars represent standard error.
Other proteins involved in RNAi and chromatin
NUCLEAR RNA POLYMERASE D1 (NRPD1) NUCLEAR RNA POLYMERASE E1 (NRPE1) RNA DEPENDENT RNA POLYMERASE2 (RDR2) DICER-LIKE3 (DCL3) ARGONAUTE4 (AGO4) DEFECTIVE IN RNA DIRECTED DNA METHYLATION 1 (DRD1) DEFECTIVE IN MERISTEM SILENCING1 (DMS1) INVOLVED IN DE NOVO 2 (IND2) SUPPRESSOR OF VARIEGATION 3-9 HOMOLOGUE 2 (SUVH2) SUPPRESSOR OF VARIEGATION 3-9 HOMOLOGUE 9 (SUVH9) (Henderson et. al, 2006)
