Specific N-methylations of HPV-16 E7 peptides alter binding to the retinoblastoma suppressor protein.

Heimbrook, David; Huber, Hans E.; Wegrzyn, Ronald; Rotberg, N S; Stauffer, Kenneth J.; Lumma, Patricia K.; Garsky, Victor M.; Oliff, Allen

doi:10.1016/s0021-9258(18)48370-6

Cited by 25 publications

(13 citation statements)

References 30 publications

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“…Since the complex between a nine-residue CR2-derived E7 peptide and the pRB small pocket (nearly identical to the pRB his domain described here) has a dissociation constant of 110 nM (46), it is reasonable to expect that the truncated proteins in this study have dissociation constants of 110 nM or lower. This assumption is further supported by the fact that a larger HPV16 E7/pRB60 complex has a dissociation constant in the low nanomolar range (29). On the basis of these data, it is reasonable to expect that very low to undetectable levels of pRB his /E7 CR2-3 dissociation occurred during this experiment.…”

Section: Purification Of E7 Cr1-3 and Of E7 Cr2-3 And Sedimentationsupporting

confidence: 52%

“…Although the CR2 region is necessary for pRB interaction, short peptides of viral oncoproteins containing only this region are not capable of displacing E2F transcription factors from pRB ( , ), suggesting that these viral oncoproteins have additional pRB-binding sites. In support of this, the apparent dissociation constant ( K d ) for an HPV16 E7 CR2-derived peptide complexed with GST-pRB60 is approximately 200 nM whereas the apparent K d for the full-length HPV16 E7/pRB60 complex is significantly lower at 1.3 nM ( , ).…”

mentioning

confidence: 87%

“…The CR2 region of both proteins contains the LXCXE amino acid sequence (where X is any amino acid, Figure , panels A and B) that is necessary for both high affinity pRB interaction ( − ) and cellular transformation ( , ). Significantly, HPV E7 is constitutively expressed in cervical carcinomas ( , ) and HPV E7-pRB interaction is necessary for HPV-mediated cellular transformation ( − ).…”

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confidence: 99%

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Oligomerization Properties of the Viral Oncoproteins Adenovirus E1A and Human Papillomavirus E7 and Their Complexes with the Retinoblastoma Protein

et al. 2000

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Human papillomavirus 16 E7 (HPV16 E7) and adenovirus 5 E1A (Ad5 E1A) are encoded by highly divergent viruses yet are functionally similar in their ability to bind the retinoblastoma (pRB) tumor suppressor protein, causing the aberrant displacement of E2F trancription factors. The amino acid residues of HPV16 E7 that are necessary for stability, for inhibition of pRB function, and for cell transformation are also necessary for E7 oligomerization. However, neither the specific oligomerization state of HPV16 E7 nor of Ad5 E1A as a function of pRB-binding has been characterized. To gain insight into HPV16 E7 and Ad5 E1A oligomerization properties, sedimentation equilibrium experiments were performed with recombinant HPV16 E7 and Ad5 E1A proteins. These studies reveal that, despite the overall functional similarities between these proteins, monomers, dimers, and tetramers of HPV16 E7 were detected while only reversible monomer-dimer association was identified for Ad5 E1A. The apparent K(d(monomer)-(dimer)) of HPV16 E7 is approximately 100-fold lower than that of a comparable region of Ad5 E1A, and it is concluded that under physiological protein concentrations HPV16 E7 exists primarily as a dimer. Sedimentation equilibrium experiments of pRB/Ad5 E1A and of pRB/HPV16 E7 complexes demonstrate that the tight association of pRB with the viral oncoproteins does not disturb their inherent oligomerization properties. Taken together, this study demonstrates significant differences between the Ad5 E1A and HPV16 E7 oligomerization states that are potentially related to their distinct structures and specific mechanisms of pRB-inactivation.

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Section: Purification Of E7 Cr1-3 and Of E7 Cr2-3 And Sedimentationsupporting

confidence: 52%

mentioning

confidence: 87%

mentioning

confidence: 99%

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Oligomerization Properties of the Viral Oncoproteins Adenovirus E1A and Human Papillomavirus E7 and Their Complexes with the Retinoblastoma Protein

et al. 2000

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“…18,23 It has been reported that incorporation of N-methyl amino acids enhances the potency and the receptor subtype selectivity of peptides. 17,[27][28][29][30][31][32] However, exceptions to these experimental observations have been reported. 27,33,34 Peptides containing single or multiple N-methylations are promising agents to disrupt protein-protein hydrogen bond interactions involving β-sheet interactions, as illustrated by inhibitors for amyloid β-peptide (Aβ) [35][36][37][38] and amylin [39][40][41][42][43][44] fibrillation.…”

Section: Introductionmentioning

confidence: 93%

The effect of N-methylation of amino acids (Ac-X-OMe) on solubility and conformation: a DFT study

et al. 2015

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N-Methylation has a significant impact on improving the oral bioavailability, lipophilicity and aqueous solubility of peptide-based lead drug structures. The selected mono-amino acid derivatives Ac-X-OMe, where X = Gly, Val, Leu, Ile, Phe, Met, Cys, Ser, Asp and His as well as their corresponding N-methylated analogues were studied. The clog P values of all N-methylated peptides are greater than those of native compounds. Quantum chemical calculations were performed to estimate the aqueous solubility of these lipophilic compounds using density functional theory (DFT). To confirm the contribution of dispersion forces on quantum chemical data, the long-range corrected (LC) hybrid density functional (ωB97X-D) was also probed for some amino acid derivatives. The ωB97X functional gave similar results. Our results reveal that after mono N-methylation of the peptide backbone, ΔGsolv becomes more negative (more water soluble) while polarizability and dipole moment are also increased. Natural atomic charges derived by natural bond orbital (NBO) analysis of N, C, and O atoms involved in amide functional group become more positive/(less negative) after N-methylation. All N-methylated amino acids have higher EHOMO (less negative) in comparison with the amino acid analogues, and in all cases N-methylation decreases EHOMO-LUMO. The calculated amide cis/trans activation energies (EA) of all the N-methylated amino acid derivatives were lower than that of native species. N-methylation of these compounds leads to an increase in lipophilicity, aqueous solubility, polarization, dipole moment and lowering of the cis/trans amide energy barrier (EA).

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“…This amino acid is located within the conserved region 2 (CR2) domain, specifically at the pRb binding site (Figure S2). The residue at position 23, part of the pRb-E7 core binding motif [65], is an important component for the E7-pRb bound conformation [66]. Interestingly, the Y amino acid (21-XLYCXE-26) is conserved in HPV16, but it is different in other papillomaviruses such as the Alpha 10 HPV6 and HPV11 , as well as the Alpha 7 HPV18 (21-XLLCXE-26) [65].…”

Section: Discussionmentioning

confidence: 99%

Phylogenomic Analysis of Human Papillomavirus Type 31 and Cervical Carcinogenesis: A Study of 2093 Viral Genomes

Pinheiro

Harari

Schiffman

et al. 2021

Viruses

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Human papillomavirus (HPV) type 31 (HPV31) is closely related to the most carcinogenic type, HPV16, but only accounts for 4% of cervical cancer cases worldwide. Viral genetic and epigenetic variations have been associated with carcinogenesis for other high-risk HPV types, but little is known about HPV31. We sequenced 2093 HPV31 viral whole genomes from two large studies, one from the U.S. and one international. In addition, we investigated CpG methylation in a subset of 175 samples. We evaluated the association of HPV31 lineages/sublineages, single nucleotide polymorphisms (SNPs) and viral methylation with cervical carcinogenesis. HPV31 A/B clade was >1.8-fold more associated with cervical intraepithelial neoplasia grade 3 and cancer (CIN3+) compared to the most common C lineage. Lineage/sublineage distribution varied by race/ethnicity and geographic region. A viral genome-wide association analysis identified SNPs within the A/B clade associated with CIN3+, including H23Y (C626T) (odds ratio = 1.60, confidence intervals = 1.17–2.19) located in the pRb CR2 binding-site within the E7 oncogene. Viral CpG methylation was higher in lineage B, compared to the other lineages, and was most elevated in CIN3+. In conclusion, these data support the increased oncogenicity of the A/B lineages and suggest variation of E7 as a contributing risk factor.

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Specific N-methylations of HPV-16 E7 peptides alter binding to the retinoblastoma suppressor protein.

Cited by 25 publications

References 30 publications

Oligomerization Properties of the Viral Oncoproteins Adenovirus E1A and Human Papillomavirus E7 and Their Complexes with the Retinoblastoma Protein

Oligomerization Properties of the Viral Oncoproteins Adenovirus E1A and Human Papillomavirus E7 and Their Complexes with the Retinoblastoma Protein

The effect of N-methylation of amino acids (Ac-X-OMe) on solubility and conformation: a DFT study

Phylogenomic Analysis of Human Papillomavirus Type 31 and Cervical Carcinogenesis: A Study of 2093 Viral Genomes

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