Novel Polymorphisms and Genetic Characteristics of the Shadow of Prion Protein Gene ( SPRN ) in Cats, Hosts of Feline Spongiform Encephalopathy

• Published in: Viruses Vol. 14; no. 5; p. 981
• Main Authors: Kim, Yong-Chan, Kim, Hyeon-Ho, Kim, Kiwon, Kim, An-Dang, Jeong, Byung-Hoon
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06.05.2022; MDPI
• Subjects: 3' Untranslated regions; Amino acid sequence; Cats; Encephalopathy; feline; Free energy; Gene polymorphism; Glycosylphosphatidylinositol; Haplotypes; Linkage disequilibrium; Livestock; mRNA; Open reading frames; Peptides; Pets; prion; Prion protein; PRNP; Protein structure; Proteins; Secondary structure; Single-nucleotide polymorphism; SNP; Spongiform encephalopathy; SPRN; Transmissible spongiform encephalopathy; United States > US; PRNP; cats; feline; SNP; FSE; prion; SPRN
• DOI: 10.3390/v14050981
• ISSN: 1999-4915

Prion diseases are transmissible spongiform encephalopathies (TSEs) caused by pathogenic prion protein (PrP ) originating from normal prion protein (PrP ) and have been reported in several types of livestock and pets. Recent studies have reported that the shadow of prion protein (Sho) encoded by the shadow of prion protein gene ( ) interacts with prion protein (PrP) and accelerates prion diseases. In addition, genetic polymorphisms in the gene are related to susceptibility to prion diseases. However, genetic polymorphisms in the feline gene and structural characteristics of the Sho have not been investigated in cats, a major host of feline spongiform encephalopathy (FSE). We performed amplicon sequencing to identify feline polymorphisms in the 623 bp encompassing the open reading frame (ORF) and a small part of the 3' untranslated region (UTR) of the gene. We analyzed the impact of feline polymorphisms on the secondary structure of mRNA using RNAsnp. In addition, to find feline-specific amino acids, we carried out multiple sequence alignments using ClustalW. Furthermore, we analyzed the N-terminal signal peptide and glycosylphosphatidylinositol (GPI)-anchor using SignalP and PredGPI, respectively. We identified three novel SNPs in the feline gene and did not find strong linkage disequilibrium (LD) among the three SNPs. We found four major haplotypes of the polymorphisms. Strong LD was not observed between and polymorphisms. In addition, we found alterations in the secondary structure and minimum free energy of the mRNA according to the haplotypes in the polymorphisms. Furthermore, we found four feline-specific amino acids in the feline Sho using multiple sequence alignments among several species. Lastly, the N-terminal signal sequence and cutting site of the Sho protein of cats showed similarity with those of other species. However, the feline Sho protein exhibited the shortest signal sequence and a unique amino acid in the omega-site of the GPI anchor. To the best of our knowledge, this is the first report on genetic polymorphisms of the feline gene.