Molecular cloning, promoter analysis and SNP identification of Italian Nicastrese and Saanen lactoferrin gene

Abstract

Lactoferrin (Lf) is an iron-binding glycoprotein found in exocrine secretions including milk. High levels of lactoferrin may have a role in the prevention of microbial infection of the mammary gland. In this report we sequenced and characterized goat lactoferrin cDNA and its promoter region in two different breeds of goat. The complete cDNA comprised 2356 nucleotides, including 38 bp at the 5′-UTR and 194 bp at the 3′-UTR. The open reading frame is 2127 bp long and it encodes a mature protein of 689 aminoacids. A total of 19 nucleotide differences, 11 of them being responsible for 8 aminoacid changes, were identified through the comparison with French, Korean and Tibetan goat lactoferrin cDNAs. About 1700 bp of the lactoferrin gene promoter were sequenced. Sequence analysis revealed a non-canonical TATA box, multiple SP1/GC elements, and other putative binding sites for transcription factors, such as NF-κB, STAT3 and AP2. Two SNPs were identified, one of which would seem to create a new putative AP2 consensus sequence. The presence of an additional AP2 binding site could be associated with quantitative differences of such protein fraction, which could enhance all the activities related to such protein, and improve mammary gland defence against bacterial infections.