Nucleic Acid Aptamer Selection Against GUS (Beta-Glucuronidase) for use as a Reporter Molecule

Nucleic Acid Aptamer Selection Against GUS (Beta-Glucuronidase) for use as a Reporter Molecule

Maneesha Gaddikoppula, Fall 2013

            GUS (Beta-Glucuronidase) is a reporter molecule that yields a colorful product when immersed in a solution containing a specific substrate. One of the common methods of GUS reporter assay is through histochemical staining which requires one of a variety of colorless substrates, such as X-Gal, resulting in a blue colorful product. Finding an aptamer against GUS can prove to be an effective diagnostic tool in the future.
            Figure 1 below illustrates the usefulness of an aptamer against GUS. When an aptamer is bound to GUS, GUS is no longer able to bind to the substrate (X-Gal), and thus will not form a colorful product. However, the aptamer can be modified such that the part of the aptamer that is not bound to GUS can bind to various other molecules specifically, such as mRNA or other protein. When that mRNA or protein is abundant, the aptamer will bind to that, leaving GUS open to bind to the substrate. This allows a colorful product to form, showing that the specific protein or mRNA is present. Had there been no mRNA or protein present, the aptamer would never have unbound from GUS, and a colorful product would never have formed. This can make an aptamer against GUS a useful diagnostic tool.

Specific Aim 1: Selection of an RNA aptamer against GUS.
GUS is a reporter molecule that forms a colorful product when bound to a substrate. An aptamer can inhibit the function of GUS, and prevent the formation of a colorful product. This process can be used as an important diagnostic tool towards other diseases.

Figure 1 illustrates the role of an aptamer against GUS when a specific mRNA or
 protein is present that the aptamer is modified to bind preferentially to.

Target Order Information:
Vendor: Ellington Lab (through Jimmy H. Golliher)
Vendor Website:
Vendor Telephone Number:
Central Lab Telephone
: 1-512-471-6445

Office Manager
: 1-512-232-3426
Cost per unit: $0
Cost per round: $0
Jefferson RA, Burgess SM, Hirsh D. “beta-Glucuronidase from Escherichia coli as a gene-fusion marker.” Proc Natl Acad Sci U S A. 1986;83:8447–8451.
Jefferson RA, Kavanagh TA, Bevan MW. “GUS fusions: beta-glucuronidase as a sensitive and versatile gene fusion marker in higher plants.” EMBO J. 1987;13:3901–3907.
Marathe SV, McEwen JE (February 1995). "Vectors with the gus reporter gene for identifying and quantitating promoter regions in Saccharomyces cerevisiae". Gene 154 (1): 105–7.

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