Difference between revisions of "Part:BBa K1150024"

Revision as of 17:05, 21 September 2013

uniCAS Histone Modifier (CMV promoter)

This device is combining the dCAS9 protein, that enables multiple gene targetting with the set-domain of the murine G9a. dCAS9 is working as a carrier for the histone methyltransferase and enables specific methylation of histone 3 Lysin 9 (H3K9me2/3) when targetted to a histone locus that is accessible for DNA binding proteins. Literature indicates that targetting the G9a Set-Domain to an open locus leads to a transcriptionally inactive state. The usage of the strong CMV promoter enables this device to be expressed in a strong manner. If weaker expression levels are needed, a device with the SV40 promoter was created. BBa_K1150023

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 targetting it to the DNA (see Snowden et.al., 2003) and repress transcription. G9a is also known to be involved in downstream signalling, but by targetting it to a specific locus we reduce the functionality to its histone modification ability. The dCAS9 protein is able to be targetted to several loci at once as it interacts with small RNAs to build up a complex that will interact with complimentary 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 targetting. The team Freiburg 2013 combined these two elements to create a transcriptional repressor that is able to repress by a specific mechanism the targetted locus. This approach offers new possibilities for fundamental epigenetic research, tissue engineering and cancer research.

Sequence and Features