MxB restricts HIV-1 infection by directly interacting with the HIV-1 core, which is made of viral capsid; however, the contribution of MxB to the HIV-1 restriction observed in alpha interferon (IFN-␣)-treated human cells is unknown. To understand this contribution, we used HIV-1 bearing the G208R capsid mutant (HIV-1-G208R), which overcomes the restriction imposed by cells expressing MxB. Here we showed that the reason why MxB does not block HIV-1-G208R is that MxB does not interact with HIV-1 cores bearing the mutation G208R. M yxovirus resistance proteins represent a family of interferon-inducible factors with a wide range of antiviral activities (1-3). The myxovirus B (MxB) gene was originally cloned from a human glioblastoma cell line treated with alpha interferon (IFN-␣) (4, 5). MxB as well as the related protein MxA belong to the dynamin-like family of proteins, which have diverse functions ranging from vesicle transport to antiviral activity (1, 6-11). The most studied dynamin-like protein that exhibits antiviral activity is MxA (1, 2). Contrary to MxB, the antiviral role of MxA has been extensively studied for viruses including influenza virus (1, 12-15), tick-borne Thogoto virus (16), African swine fever virus (17), hepatitis B virus (18), and La Crosse virus (19,20). The antiviral activity of the long form of MxB was recently described (9, 21-23); these investigations led to the discovery that the IFN-␣-inducible protein MxB blocks HIV-1 infection.Genetic evidence suggested that the HIV-1 capsid is the determinant for the ability of MxB to block HIV-1 infection (9,22,23). In agreement with these findings, we recently demonstrated that MxB binds to the HIV-1 capsid and correlated the ability of MxB to block HIV-1 infection with inhibition of uncoating (24). We also showed that the ability of MxB to block infection requires a capsid binding domain and an oligomerization domain provided by the 90 N-terminal and the 143 C-terminal amino acids of MxB, respectively (24). In addition, the work of others and our work showed that the 90 N-terminal amino acids of MxB are important for its ability to bind capsid and restrict HIV-1 infection (24)(25)(26).MxB contains a previously described putative nuclear localization signal on its N-terminal 25 amino acids (4). Deletion of the N-terminal 25 amino acids annihilates the ability of MxB to block HIV-1 infection and to bind to the HIV-1 core (23,24,27). Mutagenic studies have revealed that the N-terminal 25 amino acids of MxB exhibit a triple-arginine motif ( 11 RRR 13 ) that is important for restriction and the ability of MxB to bind to the HIV-1 core (28, 29). HIV-1 CA-NC expression and purification. The CA-NC proteins of HIV-1 and HIV-1 bearing the G208R capsid mutant (HIV-1-G208R) were expressed, purified, and assembled as previously described (30). MATERIALS AND METHODS CellMxB binding to in vitro-assembled HIV-1 and HIV-1-G208R CA-NC complexes. HEK 293T cells were transfected with a plasmid expressing the wild-type MxB protein. Forty-eight hours after t...

Opportunistic pathogens such as Candida species can use carboxylic acids, like acetate and lactate, to survive and successfully thrive in different environmental niches. These nonfermentable substrates are frequently the major carbon sources present in certain human body sites, and their efficient uptake by regulated plasma membrane transporters plays a critical role in such nutrient-limited conditions. Here, we cover the physiology and regulation of these proteins and their potential role in Candida virulence. This review also presents an evolutionary analysis of orthologues of the Saccharomyces cerevisiae Jen1 lactate and Ady2 acetate transporters, including a phylogenetic analysis of 101 putative carboxylate transporters in twelve medically relevant Candida species. These proteins are assigned to distinct clades according to their amino acid sequence homology and represent the major carboxylic acid uptake systems in yeast. While Jen transporters belong to the sialate:H+ symporter (SHS) family, the Ady2 homologue members are assigned to the acetate uptake transporter (AceTr) family. Here, we reclassify the later members as ATO (acetate transporter ortholog). The new nomenclature will facilitate the study of these transporters, as well as the analysis of their relevance for Candida pathogenesis.

HIV-1 arose as the result of spillover of simian immunodeficiency viruses (SIVs) from great apes in Africa, namely from chimpanzees and gorillas. Chimpanzees and gorillas were, themselves, infected with SIV after virus spillover from African monkeys. During spillover events, SIV is thought to require adaptation to the new host species. The host barriers that drive viral adaptation have predominantly been attributed to restriction factors, rather than cofactors (host proteins exploited to promote viral replication). Here, we consider the role of one cofactor, RanBP2, in providing a barrier that drove viral genome evolution during SIV spillover events. RanBP2 (also known as Nup358) is a component of the nuclear pore complex known to facilitate nuclear entry of HIV-1. Our data suggest that transmission of SIV from monkeys to chimpanzees, and then from chimpanzees to gorillas, both coincided with changes in the viral capsid that allowed interaction with RanBP2 of the new host species. However, human RanBP2 subsequently provided no barrier to the zoonotic transmission of SIV from chimpanzees or gorillas, indicating that chimpanzee- and gorilla-adapted SIVs are pre-adapted to humans in this regard. Our observations are in agreement with RanBP2 driving virus evolution during cross-species transmissions of SIV, particularly in the transmissions to and between great ape species.

Saccharomyces cerevisiae is the most commonly used yeast in wine, beer, and bread fermentations. However, Torulaspora delbrueckii has attracted interest in recent years due to its properties, ranging from its ability to produce flavor- and aroma-enhanced wine to its ability to survive longer in frozen dough. In this work, publicly available genomes of T. delbrueckii were explored and their annotation was improved. A total of 32 proteins were additionally annotated for the first time in the type strain CBS1146, in comparison with the previous annotation available. In addition, the annotation of the remaining three T. delbrueckii strains was performed for the first time. eggNOG-mapper was used to perform the functional annotation of the deduced T. delbrueckii coding genes, offering insights into its biological significance, and revealing 24 clusters of orthologous groups (COGs), which were gathered in three main functional categories: information storage and processing (28% of the proteins), cellular processing and signaling (27%), and metabolism (23%). Small intraspecies variability was found when considering the functional annotation of the four available T. delbrueckii genomes. A comparative study was also conducted between the T. delbrueckii genome and those from 386 fungal species, revealing a high number of homologous genes with species from the Zygotorulaspora and Zygosaccharomyces genera, but also with Lachancea and S. cerevisiae. Lastly, the phylogenetic placement of T. delbrueckii was clarified using the core homologs that were found across 204 common protein sequences of 386 fungal species and strains.

The smartphone and tablet revolution has changed how geologists work in the field, but now the community must come up with standards to tame the flood of data.