Birds exhibit extraordinary mobility and remarkable navigational skills, obtaining guidance cues from the Earth's magnetic field for orientation and long-distance movement. Bird species also show tremendous diversity in navigation strategies, with considerable differences even within the same taxa and among individuals from the same population. The highly conserved iron and iron-sulfur cluster binding magnetoreceptor (MagR) protein is suggested to enable animals, including birds, to detect the geomagnetic field and navigate accordingly. Notably, MagR is also implicated in other functions, such as electron transfer and biogenesis of iron-sulfur clusters, raising the question of whether variability exists in its biochemical and biophysical features among species, particularly birds. In the current study, we conducted a comparative analysis of MagR from two different bird species, including the migratory European robin and the homing pigeon. Sequence alignment revealed an extremely high degree of similarity between the MagRs of these species, with only three sequence variations. Nevertheless, two of these variations underpinned significant differences in metal binding capacity, oligomeric state, and magnetic properties. These findings offer compelling evidence for the marked differences in MagR between the two avian species, potentially explaining how a highly conserved protein can mediate such diverse functions.
鸟类拥有令人惊叹的导航能力，它们可以利用地球磁场作为精准定位和长距离飞行的导航线索。鸟类在导航模式和策略上表现出巨大的多样性，即使在同一分类群甚至同一种群的不同个体之间也有相当大的差异。但作为动物磁导航的关键蛋白磁受体MagR是一个高度保守的铁和铁硫簇结合蛋白，那么，在不同物种，尤其是不同鸟类之间，MagR的生化与生物物理性质是否和序列一样高度保守？此外，MagR还被报道在电子传递和铁硫簇生物合成等生物过程中均发挥重要功能。一个序列高度保守的蛋白如何介导多种多样的生物学功能？该研究对迁徙鸟类欧洲知更鸟和归巢鸟类鸽子的磁受体MagR进行了比较分析。序列比对显示这两个物种的MagR之间具有极高的相似性，仅有三处氨基酸的序列的不同。然而，我们的研究表明其中两处氨基酸差异足以导致MagR的金属结合能力和聚集状态的显著不同，并进而影响到磁学性质的差异。我们的研究通过令人信服的实验证据表明序列高度保守的Mag，在鸟类的不同物种中存在生化与生物物理性质上的显著差异，同时也暗示着在生物系统中，一个高度保守的蛋白完全可能承担多种不同的功能。.
Keywords: Animal navigation; Conserved protein; Diverse navigation pattern; Homing and migration; Magnetoreceptor (MagR).