The zinc metalloprotease ZMPSTE24 plays a critical role in nuclear lamin biology by cleaving the prenylated and carboxylmethylated 15-amino acid tail from the C-terminus of prelamin A to yield mature lamin A. A defect in this proteolytic event, caused by a mutation in the lamin A gene (LMNA) that eliminates the ZMPSTE24 cleavage site, underlies the premature aging disease Hutchinson-Gilford Progeria Syndrome (HGPS). Likewise, mutations in the ZMPSTE24 gene that result in decreased enzyme function cause a spectrum of diseases that share certain features of premature aging. Twenty human ZMPSTE24 alleles have been identified that are associated with three disease categories of increasing severity: mandibuloacral dysplasia type B (MAD-B), severe progeria (atypical 'HGPS') and restrictive dermopathy (RD). To determine whether a correlation exists between decreasing ZMPSTE24 protease activity and increasing disease severity, we expressed mutant alleles of ZMPSTE24 in yeast and optimized in vivo yeast mating assays to directly compare the activity of alleles associated with each disease category. We also measured the activity of yeast crude membranes containing the ZMPSTE24 mutant proteins in vitro. We determined that, in general, the residual activity of ZMPSTE24 patient alleles correlates with disease severity. Complete loss-of-function alleles are associated with RD, whereas retention of partial, measureable activity results in MAD-B or severe progeria. Importantly, our assays can discriminate small differences in activity among the mutants, confirming that the methods presented here will be useful for characterizing any new ZMPSTE24 mutations that are discovered.

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A short review of first‐ and second‐year German instructional material in the U.S. shows that, by design, cultural competence is either frequently conveyed in isolation from other language skills, or culture topics are approached merely in a utilitarian way to test comprehension or practice grammar. The contribution at hand presents a multi‐modal, documentary‐based lesson design on gentrification in Berlin. Students are encouraged to creatively employ their language skills to asses, interpret, and respond to information conveyed in the documentary film and develop intercultural empathy for a contemporary social justice issue in Germany.

The mammalian target of rapamycin (mTOR), a protein in the phosphoinositide 3-kinase (PI3K) pathway important to cell cycle regulation, is frequently activated in cancer. This signaling pathway regulates cell growth and metabolism, and when dysregulated in cancer, it contributes to tumor angiogenesis and growth. mTOR contains two distinct complexes, MTORC1, and MTORC2. MTORC1 plays a role in biosynthesis, while MTORC2 helps with cellular metabolism. It has been shown that mTOR knockout models are embryonically lethal to mice. However, lower levels of functional mTOR have been shown to be beneficial and slow cancer progression. Allelic variation occurs within inbred strains of mice, including BALB/c mice. One allelic variant in mTOR, R628C, which contributes to tumor susceptibility has been identified in BALB/c mice. This single amino acid change occurs in the HEAT repeats of mTOR. HEAT repeats have been shown to facilitate binding partner interactions, dimerization, and localization. Studies on mutations found within the HEAT repeats in several proteins have altered protein function and emphasize the structural importance of HEAT repeats. The goal of this study is to further elucidate the functional significance of HEAT repeats in TOR function and how allelic variation in the HEAT repeats may contribute to tumor susceptibility. Characterization of this allelic variant has shown stress inputs, such as irradiation, lead to a more severe phenotype and reduced mTORC1/2 signaling. Subsequent in vitro studies using a tetracycline inducible expression system (T-RExTM) have shown differential binding to mTORC1/2 complex partners in cells expressing the Balb/c allele. Additional studies are being performed to assess other complex binding partners, dimerization state and localization of the allelic variant. Our findings will model mTOR signaling activation mechanisms in humans to aid in development of new cancer treatments. Note: This abstract was not presented at the meeting. Citation Format: Patricia A. Wiley, Joy Gary, Zaw Phyo, Shuling Zhang, Amanda Sciorillo, Dorian Fraizer. Phenotypic characterization of allelic variation within the HEAT repeats of the mechanistic target of rapamycin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3410. doi:10.1158/1538-7445.AM2017-3410