Background: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterised by the development of hamartomas in a variety of organs and tissues. The disease is caused by mutations in either the TSC1 gene on chromosome 9q34, or the TSC2 gene on chromosome 16p13.3. The TSC1 and TSC2 gene products, TSC1 and TSC2, form a protein complex that inhibits signal transduction to the downstream effectors of the mammalian target of rapamycin (mTOR). Recently it has been shown that missense mutations to the TSC1 gene can cause TSC. Methods: We have used in vitro biochemical assays to investigate the effects on TSC1 function of TSC1 missense variants submitted to the Leiden Open Variation Database. Results: We identified specific substitutions between amino acids 50 and 190 in the N-terminal region of TSC1 that result in reduced steady state levels of the protein and lead to increased mTOR signalling. Conclusion: Our results suggest that amino acid residues within the N-terminal region of TSC1 are important for TSC1 function and for maintaining the activity of the TSC1-TSC2 complex.

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Keywords Mammalia, amino acid substitution, amino terminal sequence, article, binding protein, cell line, comparative study, controlled study, fluorescence microscopy, genetic variability, genetics, human, human cell, in vitro study, mammalian target of rapamycin, missense mutation, protein function, protein kinase, protein stability, signal transduction, tuberin, tuberous sclerosis, tuberous sclerosis complex 1 protein, tumor suppressor protein, unclassified drug
Persistent URL dx.doi.org/10.1186/1471-2350-10-88, hdl.handle.net/1765/17853
Citation
Mozaffari, E, Hoogeveen-Westerveld, M, Kwiatkowski, D, Sampson, J, Ekong, R, Povey, S, … Nellist, M.D. (2009). Identification of a region required for TSC1 stability by functional analysis of TSC1 missense mutations found in individuals with tuberous sclerosis complex. B M C Medical Genetics, 10, 88–88. doi:10.1186/1471-2350-10-88