Drug Phosphorylation and Aging

腺苷酸激酶2(AK2)是通过腺嘌呤核苷酸相互转化来调节细胞内环境平衡的关键因子 ATP、ADP和AMP。我们最近证明了AK2在抗逆转录病毒的激活中起着至关重要的作用 药物替诺福韦(TFV)在细胞和组织中，这些细胞和组织可能是艾滋病毒感染的部位。TFV是一种核苷酸反转 转录酶抑制剂，作为替诺福韦异丙酚前体药物与其他药物联合治疗 艾滋病毒的治疗。TFV需要两个连续的磷酸化步骤才能成为药理上的 激活。替诺福韦也是FDA批准的唯一HIV暴露前预防(PrEP)的一种成分 养生法。AK2是一种TFV激活蛋白，这促使我们对人类基因组DNA进行了测序 并确定可能影响TFV激活的AK2基因变异。到目前为止，体外研究 已经揭示，这些变体中的几个确实影响了AK2对TFV的活性。在向前迈进的过程中，一个 将专门测试衰老对AK2表达和活性的影响。确定TFV的活性是否- 激活激酶，尤其是AK2，在老年人和年轻人中可能表现出不同的活性。 由于老年人(≥，50岁)约占每年新增艾滋病毒感染者的17%，这一点非常重要。 这项建议的目的是：1)测定TFV水平和TFV的磷酸化代谢物 循环中的CD4+T细胞是HIV感染的关键靶点，并决定药物/代谢物的水平 老年人(65-80岁)和年轻人(18-30岁)之间的差异；2)检验假设 激活TFV的激酶在老年人(65-80岁)和年轻人(年龄)中的表达存在差异 18-30)在循环的CD4+T细胞中使用单细胞蛋白质组学。

Adenylate kinase 2 (AK2) is a key regulator of cellular homeostasis via the interconversion of adenine nucleotides ATP, ADP, and AMP. We recently demonstrated that AK2 plays a crucial role in the activation of the antiretroviral drug tenofovir (TFV) in cells and tissues that are putative sites of HIV infection. TFV is a nucleotide reverse transcriptase inhibitor that is prescribed as a tenofovir disoproxil prodrug in combination with other drugs for the treatment of HIV. TFV requires two sequential phosphorylation steps in order to become pharmacologically active. Tenofovir disoproxil is also a component of the only FDA approved HIV pre-exposure prophylaxis (PrEP) regimen. The identification of AK2 as a TFV-activating kinase spurred us to sequence the human genomic DNA of ~1200 individuals and identify AK2 genetic variants that could impact TFV activation. Thus far, in vitro studies have revealed that several of these variants do indeed impact AK2 activity towards TFV. In moving forward, an effect of aging on AK2 expression and activity will be tested specifically. Determining whether the activity of TFV- activating kinases, particularly AK2, could exhibit differential activity in older versus younger adults is of importance since older adults (≥50 years of age) account for an approximate 17% of new HIV infections annually. The aims of this proposal are to: 1) measure the levels of TFV and phosphorylated metabolites of TFV in single circulating CD4+ T cells that are key targets for HIV infection, and determine whether the drug/metabolite levels differ between older adults (ages 65-80) and younger adults (ages 18-30); 2) test the hypothesis that the patterns of expression of kinases that activate TFV are divergent in older adults (ages 65-80) versus younger adults (ages 18-30) in circulating CD4+ T cells using single cell proteomics.