In PLoS Biology this week, a team led by investigators at Harvard reports that the TRIM5 gene suppresses cross-species transmission of simian immunodeficiency viruses of sooty mangabeys "and selects for emergence of resistant variants." The team analyzed cross-species transmission of SIVsm in two groups of rhesus macaques and "found a significant effect of TRIM5 genotype on viral replication levels." In SIVsmE543-3-infected animals, the "TRIM5 genotype correlated with approximately 100-fold to 1,000-fold differences in viral replication levels." Using cell culture assays, the authors say they saw that the "same TRIM5 alleles associated with viral suppression in vivo blocked infectivity of two SIVsm strains."
In a paper published in PLoS One this week, investigators at the University of Illinois at Urbana-Champaign, the J. Craig Venter Institute, and Baylor College of Medicine report their comparative genomics study of Gardnerella vaginalis strains. In sequencing three strains of G. vaginalis, the researchers found that "each strain has significant virulence potential, although genomic and metabolic differences, such as the ability to degrade mucin, indicating that the detection of G. vaginalis in the vaginal tract provides only partial information on the physiological potential of the organism.
Investigators at the University of Texas MD Anderson Cancer Center this week show that "CREB inhibits AP-2α expression to regulate the malignant phenotype of melanoma." Specifically, they found that "both inhibition of PKA-dependent CREB phosphorylation, as well as silencing of CREB expression by shRNA, restored AP-2α protein expression in two metastatic melanoma cell lines." Loss of AP-2α expression in metastatic melanoma, the team reports, involves CREB binding at the AP-2α promoter as well as CREB-induced overexpression of E2f-1, an oncogenic transcription factor. Further, the team writes, "upregulation of AP-2α expression following CREB silencing increases endogenous p21Waf1 and decreases MCAM/MUC18, both known to be downstream target genes of AP-2α involved in melanoma progression."
Researchers at the Technical University of Denmark report a on a draft sequence of the Campylobacter jejuni strain M1 genome. In examining this strain, combined with the 12 other C. jejuni genomes that have been published, the authors have identified the organism's pan-genome, core-genome, and auxiliary genes unique to specific strains. "The pan-genome contains 2,427 gene families, whilst the core genome comprised 1,295 gene families, or about two-thirds of the gene content of the average of the sequenced C. jejuni genomes," the authors write.