据一篇发表于9月28日PLoS ONE杂志网络版的研究报告，多伦多大学的研究人员发现了阮病毒基因的进化祖先，该研究或许能给科学家对朊蛋白的致病机制有一个全新的认识。
朊病毒能导致多种神经退行性疾病，如克雅氏病(CJD)，牛海绵状脑病(BSE) 慢性消耗病(CWD)等。研究人员Gerold Schmitt-Ulms等人对朊蛋白家族各个成员的生理功能进行研究。课题组的分析表明朊病毒基因是由古老的金属离子转运体ZIP家族进化而来。ZIP蛋白家族主要负责细胞膜内外锌离子或其他金属离子的转运工作。
研究人员发现两种金属转运体ZIP6和ZIP10与哺乳动物中朊蛋白的生理功能非常接近。ZIP6和ZIP10在脑部组织中表达水平很高，并且研究人员发现，朊蛋白和ZIP蛋白含有大量相似的氨基酸序列和高度相似的空间结构。
ZIP家族和朊蛋白之间的这种联系或将为研究人员研究朊蛋白提供全新的视角。（生物谷bioon.com）
生物谷推荐原始出处：
PLoS ONE 4(9): e7208. doi:10.1371/journal.pone.0007208
Evolutionary Descent of Prion Genes from the ZIP Family of Metal Ion Transporters
Gerold Schmitt-Ulms1,2*, Sepehr Ehsani1,2, Joel C. Watts1,2,3, David Westaway5, Holger Wille3,4
1 Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario, Canada, 2 Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada, 3 Institute for Neurodegenerative Diseases, University of California San Francisco, San Francisco, California, United States of America, 4 Department of Neurology, University of California San Francisco, San Francisco, California, United States of America, 5 Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, Alberta, Canada
In the more than twenty years since its discovery, both the phylogenetic origin and cellular function of the prion protein (PrP) have remained enigmatic. Insights into a possible function of PrP may be obtained through the characterization of its molecular neighborhood in cells. Quantitative interactome data demonstrated the spatial proximity of two metal ion transporters of the ZIP family, ZIP6 and ZIP10, to mammalian prion proteins in vivo. A subsequent bioinformatic analysis revealed the unexpected presence of a PrP-like amino acid sequence within the N-terminal, extracellular domain of a distinct sub-branch of the ZIP protein family that includes ZIP5, ZIP6 and ZIP10. Additional structural threading and orthologous sequence alignment analyses argued that the prion gene family is phylogenetically derived from a ZIP-like ancestral molecule. The level of sequence homology and the presence of prion protein genes in most chordate species place the split from the ZIP-like ancestor gene at the base of the chordate lineage. This relationship explains structural and functional features found within mammalian prion proteins as elements of an ancient involvement in the transmembrane transport of divalent cations. The phylogenetic and spatial connection to ZIP proteins is expected to open new avenues of research to elucidate the biology of the prion protein in health and disease.
