Chemical Genetics
Chemical genetics is the study of small molecule and protein interactions. Small molecules alter protein function, providing insight in to the function and biological role of a protein. Small molecule reagents that enable specific interaction with proteins play a crucial role in research and medicine [1]. ChemBank is a chemical library database that organizes small molecules and the proteins they interact with.
No specific small molecules have been identified that interact with the CTLA4 protein. However, there are several different engineered monoclonal antibodies that recognize the Ig-like domain of CTLA4. These antibodies have been useful in tagging CTLA protein in vitro as well as acting as receptor antagonists. Unlike small molecules, antibodies suffer from practical disadvantages such as their complicated architecture and function. [2]
The use of chemical genetics is common in research and medicine. Application of this method to CTLA4 and Grave's disease could result in recovered intracellular trafficking and cell surface expression.
No specific small molecules have been identified that interact with the CTLA4 protein. However, there are several different engineered monoclonal antibodies that recognize the Ig-like domain of CTLA4. These antibodies have been useful in tagging CTLA protein in vitro as well as acting as receptor antagonists. Unlike small molecules, antibodies suffer from practical disadvantages such as their complicated architecture and function. [2]
The use of chemical genetics is common in research and medicine. Application of this method to CTLA4 and Grave's disease could result in recovered intracellular trafficking and cell surface expression.
MicroarrayMicroarrays are used to quantify the gene expression levels in various cells by measuring mRNA levels. The technique involves hybridizing sample mRNA to oligonucleotide probes attached to a solid surface. Florescent tags are read by a computer to produce a visualization of gene expression patterns. This high throughput method allows researchers to investigate a large number of genes from various tissues very quickly. The method is useful in identifying various gene expressions patterns under disease or treatment conditions. [3]
GEO (Gene Expression Omnibus) is an online database for microarray experiments. No microarray experiments were found that provide conclusive evidence linking CTLA4 to Grave's Disease. Future microarrays may show decreased CTLA4 expression with respect to Grave's disease. Future microarrays may also show unaltered expression of CTLA4 if a mutation is disrupting the function of CTLA4 but not its expression. |
RNA Interference (RNAi)
RNAi uses double stranded RNA to silence expression of a gene by targeting messenger RNA. When mRNA is destroyed, the gene product cannot be translated into a functional protein, effectively silencing the expression of a gene. [5] RNAi is a powerful tool for targeting a specific gene and analyzing the resulting phenotype. Most experiments are done in model organisms such as fruit flies, zebrafish, and C. elegans.
There are no known RNAi phenotypes described for CTLA4. This is expected as there is no CTLA4 homolog in the model organisms. Mice experience lymphoproliferative disorders when CTLA4 is mutated, resulting in lethality within about three weeks of life [6]. Any RNAi experiment done in mice would likely result in very early lethality, which is not useful to the researcher.
There are no known RNAi phenotypes described for CTLA4. This is expected as there is no CTLA4 homolog in the model organisms. Mice experience lymphoproliferative disorders when CTLA4 is mutated, resulting in lethality within about three weeks of life [6]. Any RNAi experiment done in mice would likely result in very early lethality, which is not useful to the researcher.
References
[1] What is chemical genetics? Genomics and Chemical Genetics - Howard Hughes Medical Institute. Retreived from http://www.hhmi.org/biointeractive/genomics/poster_a2.html
[2] Schönfeld D, Matschiner G, Chatwell L, Trentmann S, Gille H, Hülsmeyer M, Brown N, et al. 2009. An engineered lipocalin specific for CTLA-4 reveals a combining site with structural and conformational features similar to antibodies. Proc Natl Acad Sci. 106(20):8198-203. doi: 10.1073/pnas.0813399106
[3] DNA Microarray Technology. National Human Genome Research Institute. Retrieved May 16, 2013 from http://www.genome.gov/10000533
[4] GEO. Gene Expression Omnibus. http://www.ncbi.nlm.nih.gov/geo/
[5] RNA Interference. Nature Reviews. Retrieved May 16, 2013 from http://www.nature.com/nrg/multimedia/rnai/index.html
[6] Ling V, Wu PW, Finnerty HF, Sharpe AH, Gray GS, Collins M. (1999). Complete sequence determination of the mouse and human CTLA4 gene loci: cross-species DNA sequence similarity beyond exon borders. Genomics. Sep 15;60(3):341-55.
[2] Schönfeld D, Matschiner G, Chatwell L, Trentmann S, Gille H, Hülsmeyer M, Brown N, et al. 2009. An engineered lipocalin specific for CTLA-4 reveals a combining site with structural and conformational features similar to antibodies. Proc Natl Acad Sci. 106(20):8198-203. doi: 10.1073/pnas.0813399106
[3] DNA Microarray Technology. National Human Genome Research Institute. Retrieved May 16, 2013 from http://www.genome.gov/10000533
[4] GEO. Gene Expression Omnibus. http://www.ncbi.nlm.nih.gov/geo/
[5] RNA Interference. Nature Reviews. Retrieved May 16, 2013 from http://www.nature.com/nrg/multimedia/rnai/index.html
[6] Ling V, Wu PW, Finnerty HF, Sharpe AH, Gray GS, Collins M. (1999). Complete sequence determination of the mouse and human CTLA4 gene loci: cross-species DNA sequence similarity beyond exon borders. Genomics. Sep 15;60(3):341-55.