Functional analysis of androglobin, a novel oxygen-binding protein associated with male infertility.

血红蛋白和肌红蛋白是两种最常见的氧结合呼吸蛋白。后基因组时代揭示了其他哺乳动物球蛋白类型的存在，包括神经球蛋白和细胞球蛋白。最近，申请者发现了一种新的高度保守的珠蛋白谱系，由具有n端蛋白酶结构域和中央珠蛋白结构域的大嵌合蛋白组成，因其在睾丸组织中的特异性表达而被命名为androglobins （Adgbs）。新生成的adgb缺陷小鼠模型的初步表征表明精子发生过程中存在发育缺陷。目前的合作项目将通过体内和体外方法全面探索Adgb的生理作用、基因调控和生物医学意义。基于Adgb的不育表型，我们将首先关注Adgb在睾丸中的特异性作用，利用睾丸和精子组织学、精子功能分析、转录组学和相互作用组研究来表征敲除表型。生物物理和生化研究将有助于澄清Adgb的假设酶或信号作用。为此，我们将使用细胞培养研究来基因修饰表达水平，从而通过功能研究来评估Adgb潜在的抗氧化作用。此外，我们将确定Adgb的亚细胞定位，并表征重组表达Adgb的物理化学性质。最后，Adgb的基因调控将通过报告基因检测和表观遗传学方法来研究病理条件下Adgb表达的调控。总的来说，我们的研究可能有助于提高对男性不育症的理解。

Hemoglobin and myoglobin represent the two most-established oxygen-binding respiratory proteins. The post-genomic era revealed the presence of additional mammalian globin types, including neuroglobin and cytoglobin. Recently, the applicants identified a novel highly conserved globin lineage, consisting of large chimeric proteins with an N-terminal protease domain and a central globin domain, named androglobins (Adgbs) because of their specific expression in testis tissue. Preliminary characterization of a newly generated Adgb-deficient mouse model suggests a developmental defect during spermatogenesis. The present collaborative project will comprehensively explore the physiological role, gene regulation and biomedical implications of Adgb using in vivo as well as in vitro approaches. Based on the infertility phenotype of Adgb, we will initially focus on the testis-specific role of Adgb, employing testes and sperm histology, sperm functionality assays, transcriptomics and interactome studies to characterize the knock-out phenotype. Biophysical and biochemical studies will help clarifying hypothetical enzymatic or signaling roles of Adgb. For this purpose we will use cell culture studies to genetically modify expression levels enabling functional studies to evaluate a potential anti-oxidative role of Adgb. Furthermore, we will determine the subcellular localization of Adgb and characterize the physico-chemical properties of recombinantly expressed Adgb. Finally, the gene regulation of Adgb will be addressed using reporter gene assays and epigenetic approaches in order to investigate the modulation of Adgb expression under pathological conditions. Collectively, our studies will likely contribute to an improved understanding of male infertility.