References of "Minner, Frederic"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailThe inhibition of the expression of the small Rho GTPase Rac1 induces differentiation with no effect on cell proliferation in growing human adult keratinocytes.
Nikolova, Ekaterina; Mitev, Vanio; Minner, Frederic et al

in Journal of Cellular Biochemistry (2008), 103(3), 857-64

Rac1 is a Rho subfamily small GTPase which is highly expressed in epidermal keratinocytes. In mice the significance of Rac1 for the maintenance of the epidermis has been controversial. In keratinocytes ... [more ▼]

Rac1 is a Rho subfamily small GTPase which is highly expressed in epidermal keratinocytes. In mice the significance of Rac1 for the maintenance of the epidermis has been controversial. In keratinocytes from human origin, the role of Rac1 in the control of growth/differentiation is still obscure. In this study we used RNA interference to induce specific inhibition of Rac1 expression in cultured human keratinocytes and analyzed the consequences on proliferation and differentiation. We found that the autocrine proliferation of keratinocytes is unaltered by Rac1 silencing. However, the suppression of Rac1 induced premature differentiation as revealed by the expression of markers (keratin 10, involucrin), but the involved mechanism is independent of the activity of p38 mitogen-activated protein kinase. Rather, we found that the effects of Rac1 silencing on keratinocytes differentiation are concomitant with negative regulation of the Ser62/Thr58 phosphorylation on the transcription factor c-myc, a mechanism known to control post-translational stability of the c-myc protein. Thus, in growing human keratinocytes, Rac1 could impede the expression of premature differentiation markers, probably by exerting positive control on c-myc activity and its binding to specific promoters. [less ▲]

Detailed reference viewed: 35 (4 ULg)
Peer Reviewed
See detailEvolution of Bovine herpesvirus 4: recombination and transmission between African buffalo and cattle
Dewals, Benjamin G ULg; Thirion, Muriel; Markine-Goriaynoff, Nicolas et al

Poster (2007, November 23)

Bovine herpesvirus 4 (BoHV 4) has been isolated from cattle throughout the world, but virological and serological studies have suggested that the African buffalo is also a natural host for this virus. We ... [more ▼]

Bovine herpesvirus 4 (BoHV 4) has been isolated from cattle throughout the world, but virological and serological studies have suggested that the African buffalo is also a natural host for this virus. We have previously found that the Bo17 gene of BoHV-4 was acquired from an ancestor of the African buffalo, probably around 1.5 Myr ago. Analysis of the variation of the Bo17 gene sequence among BoHV-4 strains suggested a relatively ancient transmission of BoHV 4 from the buffalo to the Bos primigenius lineage, followed by a host dependent split between zebu and taurine BoHV 4 strains. In the present study, the evolutionary history of BoHV-4 was investigated by analysis of five gene sequences from each of nine strains representative of the viral species: three isolated from African buffalo in Kenya, and six from cattle from Europe, N. America and India. No two gene sequences had the same evolutionary tree, indicating that recombination has occurred between divergent lineages: six recombination events were delineated for these sequences. Nevertheless, exchange has been infrequent enough that a clonal evolutionary history of the strains could be discerned, upon which the recombination events were superimposed. The dates of divergence among BoHV-4 lineages were estimated from synonymous nucleotide substitution rates. The inferred evolutionary history suggests that African buffalo were the original natural reservoir of BoHV-4, and that there have been at least three independent transmissions from buffalo to cattle, probably via intermediate hosts, and – at least in the case of N. American strains – within the last 500 years. [less ▲]

Detailed reference viewed: 10 (4 ULg)
Peer Reviewed
See detailPhylogeographical analysis of bovine herpesvirus 4: demonstration that inter strain recombination events took place after acquisition of the bo17 gene from an ancestor of the african buffalo
Dewals, Benjamin G ULg; Markine-Goriaynoff, Nicolas; de Fays, Kataline et al

Poster (2005, March)

Recently, our phylogenetic study revealed that the Bovine herpesvirus 4 (BoHV 4) Bo17 gene has been acquired from an ancestor of the African buffalo around 1.5 million years ago, implying that cattle ... [more ▼]

Recently, our phylogenetic study revealed that the Bovine herpesvirus 4 (BoHV 4) Bo17 gene has been acquired from an ancestor of the African buffalo around 1.5 million years ago, implying that cattle subsequently acquired BoHV 4 by cross species transmission (Markine-Goriaynoff et al., 2003, 77:1784-1792). In the present study, we pursued our investigation on the origin and the evolution of BoHV 4. Firstly, with the goal in mind to further precise the origin of the Bo17 gene, the C2GnT M gene sequence was determined for each subspecies of African buffalo and for three types of Asian buffalo. Phylogenetic analyses of these new sequences further supported our conclusion that the Bo17 gene has been acquired from an ancestor of the African buffalo, possibly of the Syncerus caffer caffer subspecies from East-Africa origin. Secondly, to investigate the phylogeographical relationships among BoHV-4 strains isolated from four different continents, phylogenetic analyses were performed based on six different regions distributed throughout the genome. Analyses of these regions revealed a clear correlation between the phylogenetic relationships among BoHV-4 strains and their geographical origin, leading to the concept of BoHV-4 geographical clades. These analyses also demonstrated that since the acquisition of the Bo17 gene, recombination events occurred at different time in the past between ancestors of actual geographical clades. These recombinations provided an opportunity to learn how after acquisition of the Bo17 gene in Africa around 1.5 million years ago, BoHV-4 has spread to the world to form phylogenetically related geographical clades. [less ▲]

Detailed reference viewed: 17 (2 ULg)
Full Text
Peer Reviewed
See detailThe core 2 beta-1,6-N-acetylglucosaminyltransferase-M encoded by bovine herpesvirus 4 is not essential for virus replication despite contributing to post-translational modifications of structural proteins.
Markine-Goriaynoff, Nicolas; Gillet, Laurent ULg; Karlsen, Odd A et al

in Journal of General Virology (The) (2004), 85(Pt 2), 355-67

The Bo17 gene of bovine herpesvirus 4 (BoHV-4) is the only virus gene known to date that encodes a homologue of the cellular core 2 beta-1,6-N-acetylglucosaminyltransferase-mucine type (C2GnT-M). Recently ... [more ▼]

The Bo17 gene of bovine herpesvirus 4 (BoHV-4) is the only virus gene known to date that encodes a homologue of the cellular core 2 beta-1,6-N-acetylglucosaminyltransferase-mucine type (C2GnT-M). Recently, our phylogenetic study revealed that the Bo17 gene has been acquired from an ancestor of the African buffalo around 1.5 million years ago. Despite this recent origin, the Bo17 sequence has spread to fixation in the virus population possibly by natural selection. Supporting the latter hypothesis, it has been shown by our group for the V. test strain that Bo17 is expressed during BoHV-4 replication in vitro, and that Bo17 expression product (pBo17) has all three enzymic activities exhibited by cellular C2GnT-M, i.e. core 2, core 4 and I branching activities. In the present study, firstly it was investigated whether encoding a functional C2GnT-M is a general property of BoHV-4 strains. Analysis of nine representative strains of the BoHV-4 species revealed that all of them express the Bo17 gene and the associated core 2 branching activity during virus replication in vitro. Secondly, in order to investigate the roles of Bo17, its kinetic class of expression was analysed and a deleted recombinant strain was produced. These experiments revealed that Bo17 is expressed as an early gene which is not essential for virus replication in vitro. However, comparison of the structural proteins, produced by the wild-type, the revertant and the deleted viruses, by 2D gels demonstrated that pBo17 contributes to the post-translational modifications of structural proteins. Possible roles of Bo17 in vivo are discussed. [less ▲]

Detailed reference viewed: 22 (3 ULg)
Full Text
Peer Reviewed
See detailL'herpèsvirus bovin de type 4 : virus pathogène ou passager?
Thiry, Etienne ULg; Markine-Goriaynoff, Nicolas; Minner, Frédéric et al

in Point Vétérinaire (2000), 31

Bovine herpesvirus type 4 (BHV-4) is a ubiquitous herpesvirus in cattle. It has been isolated from animals showing a wide variety of clinical signs but few of the isolates have proven experimental ... [more ▼]

Bovine herpesvirus type 4 (BHV-4) is a ubiquitous herpesvirus in cattle. It has been isolated from animals showing a wide variety of clinical signs but few of the isolates have proven experimental pathogenicity. Species that are susceptible to BHV-4 include animals other than ruminants, notably cats and, surprisingly, a primate the owl monkey (Aotus trivirgatus). BHV-4 exists as a latent infection in mononuclear cells. In cattle, BHV-4 has been isolated in animals exhibiting ocular and respiratory conditions and it has been found in females with genital tract conditions such as post-partum metritis and vulvovaginitis. There is some epidemiological and experimental evidence that BHV-4 may be a cause of bovine abortion. There is no vaccine available in Europe and prevention is exclusively by hygiene measures. [less ▲]

Detailed reference viewed: 50 (4 ULg)