Cloning and Characterization of cDNA of ZmZIP4 Encoding a Zinc Transporter from Maize

A zinc transporter gene,ZmZIP4,was isolated by RT-PCR from maize.There is 1 161 bp in length for the Open Reading Frame(ORF) of this gene,which encodes a 38.66 kD protein with 386 amino acids and contains 7 transmembrane domains.The isoelectric point of the gene is 7.5.Based on analysis of sequence alignment and phylogenetic tree of amino acids,it was indicated that there is the greatest homology between ZmZIP4 and OsZIP4.The results of transient expression of the EGFP-ZmZIP4 protein in onion epidermal cell showed that ZmZIP4 is localized in plasma membrane.These results indicated that the ZmZIP4 should play an important role in maize response to low zinc stresses as a zinc transporter.