Melissa Reveles' harmonin aptamer project (2014)

Nucleic Acid Aptamer Selection against Human USH1C/Harmonin for Development of Diagnostic for Usher Syndrome

Usher syndrome (USH) is the most common cause of combined deafness and blindness in the United States (William et al, 2010). The frequency of Usher syndrome in the US is estimated to be about 1/6000 (William et al, 2010). Usher syndrome is known to be caused by mutations in various genes. It is classified into three types, with type one being the most severe. USH1C is a gene that encodes for Harmonin, a scaffold protein that is important in the development of the eye and ear ( Kikkawa et al 2003). Mutations in this protein lead to USH (William et al, 2010) ( Kikkawa et al 2003). There is no cure for Usher syndrome ( William et al, 2010). The best treatment plan is early detection in order to develop a custom treatment program for the individual often involving a cochlear implantation, training in communication methods such sign language, orientation training and more (Kikkawa et al 2003).

Detecting the protein and possibly inhibiting it is a method that can be used to combat the production of USH1C mutations. This can be done with the use of an aptamer. An aptamer is a nucleic acid species that binds with high affinity to a molecular target which could be a protein or small molecule, in this case USH1C. An aptamer against USH1C could be used as a diagnostic to easily detect USH in the body. It could also have many therapeutic applications and can prove to be very promising but the aim of this research will be focusing on its diagnostic abilities.

In order to find the appropriate aptamer an in vitro selection will be performed. In an in vitro selection, target bound nucleic acids are enriched from random sequence populations (i.e. pools). Through the selection a sequence of RNA that binds with high affinity to the target is generated. This selection will be done using a bead-based method. Generating an aptamer for Harmonin would aid the discovery of a new diagnostic for Usher Syndrome.

The item that will be purchased is Human USH1C/ Harmonin Protein (His Tag). It will be purchased from Sino Biological Inc. (www.sinobiological.com), phone number: +86-400-890-9989. The catalog number is 10613-H07E-50, and has a molecular weight of 63,700 g/mol. The cost of it is $178/50 ug which comes out to be about $34.29/round of selection (Sino Biological (2014).