5 research outputs found
Genome polymorphisms in HPV6s from benign respiratory and genital lesions
Get PDFComplete genomes of HPV6s from respiratory papillomatoses and from a genital condyloma (single episode) were determined and compared to published genomes.
Three adult onset respiratory papillomatoses (one solitary and two recurrent papillomas with two and six episodes) were HPV6b positive and five HPV6vcs (in the condyloma, in two juvenile papillomatoses with four and five recurrences and in two adult onset papillomatoses with seven and twelve episodes) were found, HPV6a was not encountered.
In HPV6b, 25 polymorphisms were identified, 17 to 21 polymorphisms in a genome. Ten were virus-specific and fifteen were characteristic to the intratypic variant group. All three HPV6b genomes clustered separately from the prototype into three different groups. Five, two and two polymorphisms were found in E1, E5a and E6 ORFs, respectively, of which those of E5a were unique. These two resulted in amino acid alteration (E39D and P78S), others were silent. Other early ORFs were conservative. Late ORFs L1 and L2 contained four and five conservative polymorphisms, respectively. In the noncoding region one, in the long control region (LCR) six polymorphisms were detected.
In HPV6vc, 22 polymorphisms were found, three to seven polymorphisms in a genome. Only one was present in all five genomes, one in three; 20 were unique. All five genomes clustered to the same large group as the reference genome, but all to different subclusters. ORFs E1, E2, E4, E5a and E6 carried three, five, one, one and two polymorphisms, respectively, of which, in contrast to HPV6b, all except two (in E1 and in E5a) were unique. Four of them led to amino acid replacement, all in the E2-E4 ORF (T116N, S144T, S246A and E340D in the E2; S246A corresponded to a S68R change in E4 ORF, the others were in the region belonging solely to E2). ORFs E5b and E7 were the same as the reference. Late ORF L1 contained one polymorphism common to all five genomes and five unique alterations. The common polymorphism led to a Y219D change. Three of the five unique polymorphisms were silent, one led to F441L and one to K449E amino acid replacement. In the noncoding region one unique, in the LCR two unique polymorphisms were detected.
HPV6vc showed considerably higher variability with multiple non-silent polymorphisms in E2-E4, while coding regions of the three HPV6bs, though different from the prototype, were more similar. LCR, in contrast, was more variable in HPV6b. These suggest that HPV6bs differ mainly in LCR activity, while in HPV6vc polymorphisms of replication proteins may be more important.
K. Szarka & G. Kardos were supported by a János Bolyai Research Scholarship of the Hungarian Academy of Science
Functional analysis of genome polymorphisms in human papillomavirus 11 associated with recurrent respiratory papillomatosis with different clinical severity
Get PDFPolymorphisms of the long control region (LCR) of human papillomavirus (HPV) 11 may modify severity of respiratory papillomatosis (RRP). We also found unique amino acid polymorphisms in virus proteins. We analysed a HPV11 genome from a novel patient, and earlier reported and newly found polymorphisms in silico to assess their role in the clinical course of RRP.
The new patient has an adult-onset RRP with moderate dysplasia. All LCRs were examined for transcription factor binding sites using the tool . In silico protein modelling (Molecular Operating Environment 2014.9) was performed on the following: i) The two polymorphisms (A476V and S486F) in L1 present in the virus from the papilloma but not from the healthy mucosa of Patient 5 with aggressive RRP. ii) E1 polymorphisms A72E and N100T in Patients 4 and 9, respectively, with moderately severe RRP. iii) E2 polymorphisms Q86K in Patient 4; S245F and N247T in Patient 9; K308R in multiple patients.
Complete genome of the newly enrolled Patient 10 contained 21 polymorphisms (16 silent, A45S in E7, S78L in E4, K308R in E2, I28F and V41L in E5a), a deletion and an insertion in the LCR; all known from other genomes. It also contains a large unique deletion in ORF E2-E4 (NT3381-3438) causing a frameshift with an early stop codon.
The identified seven LCR polymorphisms resulted in 28 new binding sites of 24 transcription factors, modified 66 binding sites of 52 transcription factors; no binding site was lost.
L1 polymorphisms are located in C-terminus playing a role in capsomer formation and possibly in heparan-sulfate binding of virions. In protein models both were involved in binding between monomers; S486F led to a new interaction with E382 and with A385 of the neighbouring monomer of the capsomer (free enthalpy -1.2 kcal/mol).
Both E1 polymorphisms are in the N-terminal regulatory region, but do not involve nuclear transport signal sequences. As this part of the protein is unstructured, structure modelling was not possible.
E2 polymorphism Q82K is located in the E1 binding domain, but due to lack of E1 model, this interaction could not be modelled. Polymorphisms S245F and N247T are in the hinge region of E2 containing phosphorylation sites involved in E2 stability and chromatin binding. As they lead to loss of one phosphorylation site and to gaining another, and alter the surface charge of E2, they may affect phosphorylation patterns. Polymorphism K308R is in the DNA binding domain, but is positioned distantly from the DNA during interaction.
The truncated E2 of the HPV11 from Patient 10 lost a large part of its DNA binding domain, and though the alpha-helix serving as DNA binding motif is preserved, its surface charge alters from basic to acidic, most probably impairing DNA binding.
In summary, protein modelling supports the role of some of these unique polymorphisms in pathogenesis of RRP.
K. Szarka was supported by János Bolyai Resarch Scholarship of the Hungarian Academy of Sciences
A poli-ADP-riboziláció szerepe a HaCaT sejtek UVB sugárzás okozta sejthalálban
No full textA poli-ADP-riboziláció szerepének vizsgálata HaCaT sejtvonalon UVB sugárzás hatására bekövetkező sejthalál során. Különböző PARP gátlószerek hatásának vizsgálata.BscBiológiag
