Protein truncation test

The protein truncation test is a way of testing large genes (e.g., NEl) for which an antibody is available. PTT can detect nonsense mutations that are peptide chain terminating. These show up, after reverse transcription/cell-free translation, as shorter-than-normal peptides in an electrophoretic gel (Eig. 3C). 

Gardner, R.J., Bobrow, M., and Roberts, R.G., 1995, The identification of point mutations in Duchenne muscular dystrophy patients by using reverse-transcription PCR and the protein truncation test, Am J Hum Genet, 57, pp 311—320. 

Gite S, Lim M, Carlson R, Olejnik J, Zehnbauer B, Rothschild K. A high throughput nonisotopic protein truncation test. Nat Biotech 2003 21 194-7. 

Hogervorst FBI, Cornelis RS, Bout M, van Vliet M, Oosterwijk fC, Ohner R, et al. Rapid detection of BRCAl mutations by the protein truncation test. Nature Genet 1995 10 208-12,... 

Protein truncation test (PTT) High sensitivity for chain terminating mutations shows position of change Chain-terminating mutations only experimentally difficult best with RNA expensive... 

Protein truncation test Highly sensitive for chain terminating Detects mutations that lead to protein... 

Isoelectric focusing of transferrin is a useful biochemical test for assisting in the diagnosis of these conditions truncation of the oligosaccharide chains of this protein alters its isolectric focusing pattern... 

Alternative mRNA maturation is frequent in tumor tissue expressing ER. In some cases it would give rise to truncated receptors that would maintain the capacity to bind hormones but would have lost their capacity as a transcription factor. Additionally, truncated receptors would be produced that would lack the capacity to bind hormones but would conserve intact their capacity to interact with DNA. In this case, the truncated receptors can become tumorigenic by stimulating the proliferation of cells uncontrolled by hormones. These receptor variants have been the object of exhaustive study at the level of mRNA in tumors of the breast, mainly estrogen-dependent tumors (Clemons et al. 2001 Garcia et al. 1988 Palmieri et al. 2002), but tests for the existence of receptor protein with these characteristics have not corroborated the expectation created by their theoretical interest. 

Two mutations were identified a splice variant that eliminated an exon and a frameshift mutation that truncated the protein. The linkage between the pseudogene polymorphism and these mutations was much stronger in Caucasians than African Americans. Thus a test for the pseudogene polymorphism in African Americans would have lower predictive values than in Caucasians. 

Heme oxygenase HO-2 has been partially purified from rat testes and the full-length protein has been expressed in an active form in E. coli (11, 61-63). Truncation of the protein at the C-terminus provides... 

As discussed above, the 22-kDa fragment (residues 1—191) retains full receptor-binding activity. To define further the minimal amount of sequence necessary for maintaining full activity, a series of carboxyl-terminal truncations was produced by site-directed mutagenesis and expressed in Escherichia coli (Lalazar et ai, 1989). The truncations comprised residues 1-166, 1-170, 1-174, and 1-183. When the truncated proteins were complexed with DMPC and tested for receptor activity. 

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