Difference between revisions of "Part:BBa K1150023"

Revision as of 15:58, 26 September 2013

uniCAS Histone Modifier (SV40 promoter)

This device is combining the dCAS9 protein, that enables multiple gene targeting with the set-domain of the murine G9a. dCAS9 is working as a carrier for this histone methyltransferase and enables specific methylation of histone 3 Lysin 9 (H3K9me2/3) when targeted to a histone locus that is accessible for DNA binding proteins. Literature indicates that targeting the G9a Set-Domain to an open locus leads to a transcriptionally inactive state. The usage of the medium strong SV40 promoter optimizes this device for means were a strong expression is suboptimal. If a strong expression is desired check [[1]].[[2]]

Usage and Biology

H3K9 methylation is a hallmark of repressed transcriptional states. The murine G9a-Set domain is able to transfer methyl groups to H3K9 when targeting it to the DNA (see Snowden et.al., 2003) and repress transcription. G9a is also known to be involved in downstream signalling, but by targeting it to a specific locus we reduce the functionality to its histone modification ability. The dCAS9 protein is able to be targeted to several loci at once as it interacts with small RNAs to build up a complex that will interact with complementary DNA strands. Its origin is the adaptive immune system of Streptococcus pyogenes called CRISPR. Hijacking this system leads to a whole new approach for multiple gene targeting. The iGEM team Freiburg 2013 combined these two elements to create a transcriptional repressor that is able to repress by a specific mechanism the targeted locus. This approach offers new possibilities for fundamental epigenetic research, tissue engineering and cancer research.

Sequence and Features