The HCPro from the Potyviridae family : an enviable multitasking Helper Component that every virus would like to have

RNA viruses have very compact genomes and so provide a unique opportunity to study how evolution works to optimize the use of very limited genomic information. A widespread viral strategy to solve this issue concerning the coding space relies on the expression of proteins with multiple functions. Members of the family Potyviridae, the most abundant group of RNA viruses in plants, offer several attractive examples of viral factors which play roles in diverse infection-related pathways. The Helper Component Proteinase (HCPro) is an essential and well-characterized multitasking protein for which at least three independent functions have been described: (i) viral plant-to-plant transmission; (ii) polyprotein maturation; and (iii) RNA silencing suppression. Moreover, multitudes of host factors have been found to interact with HCPro. Intriguingly, most of these partners have not been ascribed to any of the HCPro roles during the infectious cycle, supporting the idea that this protein might play even more roles than those already established. In this comprehensive review, we attempt to summarize our current knowledge about HCPro and its already attributed and putative novel roles, and to discuss the similarities and differences regarding this factor in members of this important viral family

Estudio del perfil de ácidos grasos de carne, cuerpo graso, tejido adiposo y sangre de caiman latirostris en cautiverio

Los lípidos son componentes importantes de las membranas celulares y juegan un papel importante en los procesos metabólicos. Están compuestos por ácidos grasos (FA) de diferentes longitudes de cadena que pueden ser saturadas o insaturadas. Los cambios en la composición de AG de la dieta podrían inducir alteraciones en la composición de AG de los tejidos

Oligonucleotides used in this study

1 table.Supplementary table with a relation of oligonucleotides used in the main article.Peer reviewe

Templates and name of primers used for PCR amplifications during the construction of the indicated plasmids are shown [1]

Supplementary table with templates and name of primers used for PCR amplifications during the construction of the indicated plasmids are shown.Peer reviewe

Templates and name of primers used for PCR amplifications during the construction of the indicated plasmids are shown [2]

1 table.Supplementary table with templates and name of primers used for PCR amplifications during the construction of the indicated plasmids are shown.Peer reviewe

Templates and name of primers used for PCR amplifications during the construction of the indicated plasmids are shown [3]

1 table.Supplementary table with templates and name of primers used for PCR amplifications during the construction of the indicated plasmids are shown.Peer reviewe

Relative concentration of the indicated nucleotides in samples from either Nicotiana benthamiana or Manihot esculenta leaves. For normalization, the average of GTP in N. benthamiana is equal to 1

1 table.Peer reviewe

Recombination and gene duplication in the evolutionary diversification of P1 proteins in the family Potyviridae

Genome structure and sequence are notably conserved between members of the family Potyviridae. However, some genomic regions of these viruses, such as that encoding the P1 protein, show strikingly high variability. In this study, some partially conserved motifs were identified upstream of the quite well-conserved protease domain located near the P1 C terminus. The irregular distribution of these motifs suggests that the potyviral P1 proteins have undergone complex evolutionary diversification. Evidence was found of recombination events in the P1 N-terminal region, similar to those reported in potyviruses of the bean common mosaic virus subgroup, but also affecting other potyviruses. Moreover, intergeneric recombination events affecting potyviruses and ipomoviruses were also observed. Evidence that these recombination events could be linked to host adaptation is provided. Specific sequence features and differences in net charge help to classify the P1 proteins of members of the family Potyviridae into two groups: those from potyviruses and rymoviruses and those from tritimoviruses. The ipomovirus Cucumber vein yellowing virus has two P1 copies arranged in tandem, the most N-terminal one being of the potyvirus type and the other being of the tritimovirus type. These findings suggest that both recombination and gene duplication have contributed to P1 evolution and helped to facilitate successful adaptation of members of the family Potyviridae to a wide range of host species. © 2007 SGM.This work was supported by grants BIO2004-02687 from the Spanish MEC, CPE03‐022‐C5 from INIA and SP22-CT-2004 from the European Union to J. A. G. and by grant AGL2004-00704 from the Spanish MEC to J. J. L.-M. Consorci CSIC-IRTA receives support from the Centre de Referència en Biotecnologia (CeRBa) of the Generalitat de Catalunya. A. V. was a recipient of an I3P fellowship from CSIC-Fondo Social Europeo.Peer Reviewe

The HCPro from the Potyviridae family : an enviable multitasking Helper Component that every virus would like to have

RNA viruses have very compact genomes and so provide a unique opportunity to study how evolution works to optimize the use of very limited genomic information. A widespread viral strategy to solve this issue concerning the coding space relies on the expression of proteins with multiple functions. Members of the family Potyviridae, the most abundant group of RNA viruses in plants, offer several attractive examples of viral factors which play roles in diverse infection-related pathways. The Helper Component Proteinase (HCPro) is an essential and well-characterized multitasking protein for which at least three independent functions have been described: (i) viral plant-to-plant transmission; (ii) polyprotein maturation; and (iii) RNA silencing suppression. Moreover, multitudes of host factors have been found to interact with HCPro. Intriguingly, most of these partners have not been ascribed to any of the HCPro roles during the infectious cycle, supporting the idea that this protein might play even more roles than those already established. In this comprehensive review, we attempt to summarize our current knowledge about HCPro and its already attributed and putative novel roles, and to discuss the similarities and differences regarding this factor in members of this important viral family

Sterol isomerase HYDRA1 interacts with RNA silencing suppressor P1b and restricts potyviral infection

Plants use RNA silencing as a strong defensive barrier against virus challenges, and viruses counteract this defence by using RNA silencing suppressors (RSSs). With the objective of identifying host factors helping either the plant or the virus in this interaction, we have performed a yeast two-hybrid screen using P1b, the RSS protein of the ipomovirus Cucumber vein yellowing virus (CVYV, family Potyviridae), as a bait. The C-8 sterol isomerase HYDRA1 (HYD1), an enzyme involved in isoprenoid biosynthesis and cell membrane biology, and required for RNA silencing, was isolated in this screen. The interaction between CVYV P1b and HYD1 was confirmed in planta by Bimolecular Fluorescence Complementation assays. We demonstrated that HYD1 negatively impacts the accumulation of CVYV P1b in an agroinfiltration assay. Moreover, expression of HYD1 inhibited the infection of the potyvirus Plum pox virus, especially when antiviral RNA silencing was boosted by high temperature or by coexpression of homologous sequences. Our results reinforce previous evidence highlighting the relevance of particular composition and structure of cellular membranes for RNA silencing and viral infection. We report a new interaction of an RSS protein from the Potyviridae family with a member of the isoprenoid biosynthetic pathway.FEDER Ministerio de Ciencia e Innovación. Grant Numbers: BIO2013-49053-R, BIO2015-73900-JIN, BIO2016-80572-