Whole-Genome Sequencing of Vero E6 (VERO C1008) and Comparative Analysis of Four Vero Cell Sublines.

The Vero cell line is an immortalized cell line established from kidney epithelial cells of the African green monkey. A variety of Vero sublines have been developed and can be classified into four major cell lineages. In this study, we determined the whole-genome sequence of Vero E6 (VERO C1008), which is one of the most widely used cell lines for the proliferation and isolation of severe acute respiratory syndrome coronaviruses (SARS-CoVs), and performed comparative analysis among Vero JCRB0111, Vero CCL-81, Vero 76, and Vero E6. Analysis of the copy number changes and loss of heterozygosity revealed that these four sublines share a large deletion and loss of heterozygosity on chromosome 12, which harbors type I interferon and CDKN2 gene clusters. We identified a substantial number of genetic differences among the sublines including single nucleotide variants, indels, and copy number variations. The spectrum of single nucleotide variants indicated a close genetic relationship between Vero JCRB0111 and Vero CCL-81, and between Vero 76 and Vero E6, and a considerable genetic gap between the former two and the latter two lines. In contrast, we confirmed the pattern of genomic integration sites of simian endogenous retroviral sequences, which was consistent among the sublines. We identified subline-specific/enriched loss of function and missense variants, which potentially contribute to the differences in response to viral infection among the Vero sublines. In particular, we identified four genes (IL1RAP, TRIM25, RB1CC1, and ATG2A) that contained missense variants specific or enriched in Vero E6. In addition, we found that V739I variants of ACE2, which functions as the receptor for SARS-CoVs, were heterozygous in Vero JCRB0111, Vero CCL-81, and Vero 76; however, Vero E6 harbored only the allele with isoleucine, resulting from the loss of one of the X chromosomes.

Sequence requirements of the FFAT-like motif for specific binding to VAP-A are revealed by NMR.

The endoplasmic reticulum transmembrane protein vesicle-associated membrane protein-associated protein (VAP) plays a central role in the formation and function of membrane contact sites (MCS) through its interactions with proteins. The major sperm protein (MSP) domain of VAP binds to a variety of sequences which are referred to as FFAT-like motifs. In this study, we investigated the interactions of eight peptides containing FFAT-like motifs with the VAP-A MSP domain (VAP-AMSP ) by solution NMR. Six of eight peptides are specifically bound to VAP-A. Furthermore, we found that the RNA-dependent RNA polymerase of severe acute respiratory syndrome coronavirus 2 has an FFAT-like motif which specifically binds to VAP-AMSP as well as other FFAT-like motifs. Our results will contribute to the discovery of new VAP interactors.