Phylogenetic and sequence analyses of insect transferrins suggest that only transferrin 1 has a role in iron homeostasis  

作　　者：Diana G.Najera Neal T.Dittmer Jacob J.Weber Michael R.Kanost Maureen J.Gorman 

机构地区：[1]Department of Biochemistry and Molecular Biophysics,Kansas State University,Manhattan,Kansas,USA

出　　处：《Insect Science》2021年第2期495-508,共14页昆虫科学（英文版）

基　　金：We thank Yoonseong Park for helpful suggestions regarding this work and Averi Baker for her help with identifying some insect transferrin sequences.This work was supported by National Science Foundation Grant 1656388 and National Institute of General Medical Sciences grant R37 GM041247.This is contribution 20-121-J from the Kansas Agricultural Experiment Station.

摘　　要：Iron is essential to life,but surprisingly little is known about how iron is managed in nonvertebrate animals.In mammals,the well-characterized transferrins bind iron and are involved in iron transport or immunity,whereas other members of the transferrin family do not have a role in iron homeostasis.In insects,the functions of transferrins are still poorly understood.The goals of this project were to identify the transferrin genes in a diverse set of insect species,resolve the evolutionary relationships among these genes,and predict which of the transferrins are likely to have a role in iron homeostasis.Our phylogenetic analysis of transferrins from 16 orders of insects and two orders of noninsect hexapods demonstrated that there are four orthologous groups of insect transferrins.Our analysis suggests that transferrin 2 arose prior to the origin of insects,and transferrins/,i,and 4 arose early in insect evolution.Primary sequence analysis of each of the insect transferrins was used to predict signal peptides,carboxyl-terminal transmembrane regions,GPI-anchors,and iron binding.Based on this analysis,we suggest that transferrins 2,and 4 are unlikely to play a major role in iron homeostasis.In contrast,the transferrin 1 orthologs are predicted to be secreted,soluble,iron-binding proteins.We conclude that transferrin 1 orthologs are the most likely to play an important role in iron homeostasis.Interestingly,it appears that the louse,aphid,and thrips lineages have lost the transferrin 1 gene and,thus,have evolved to manage iron without transferrins.

关 键 词：HEMOLYMPH INSECT iron homeostasis melanotransferrin PHYLOGENY TRANSFERRIN 

分 类 号：Q96[生物学—昆虫学]