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Title: Vaccinia Virus N1L Protein Resembles a B Cell Lymphoma-2 (Bcl-2) Family Protein

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Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Protein Science; Journal Volume: 16
Country of Publication:
United States
national synchrotron light source

Citation Formats

Aoyagi,M., Zhai, D., Jin, C., Aleshin, A., Stec, B., Reed, J., and Liddington, R. Vaccinia Virus N1L Protein Resembles a B Cell Lymphoma-2 (Bcl-2) Family Protein. United States: N. p., 2007. Web.
Aoyagi,M., Zhai, D., Jin, C., Aleshin, A., Stec, B., Reed, J., & Liddington, R. Vaccinia Virus N1L Protein Resembles a B Cell Lymphoma-2 (Bcl-2) Family Protein. United States.
Aoyagi,M., Zhai, D., Jin, C., Aleshin, A., Stec, B., Reed, J., and Liddington, R. Mon . "Vaccinia Virus N1L Protein Resembles a B Cell Lymphoma-2 (Bcl-2) Family Protein". United States. doi:.
title = {Vaccinia Virus N1L Protein Resembles a B Cell Lymphoma-2 (Bcl-2) Family Protein},
author = {Aoyagi,M. and Zhai, D. and Jin, C. and Aleshin, A. and Stec, B. and Reed, J. and Liddington, R.},
abstractNote = {},
doi = {},
journal = {Protein Science},
number = ,
volume = 16,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
  • Poxviruses encode immuno-modulatory proteins capable of subverting host defenses. The poxvirus vaccinia expresses a small 14-kDa protein, N1L, that is critical for virulence. We report the crystal structure of N1L, which reveals an unexpected but striking resemblance to host apoptotic regulators of the B cell lymphoma-2 (Bcl-2) family. Although N1L lacks detectable Bcl-2 homology (BH) motifs at the sequence level, we show that N1L binds with high affinity to the BH3 peptides of pro-apoptotic Bcl-2 family proteins in vitro, consistent with a role for N1L in modulating host antiviral defenses.
  • We have previously demonstrated that the anti-apoptotic protein BAD is expressed in normal human breast tissue and shown that BAD inhibits expression of cyclin D1 to delay cell-cycle progression in breast cancer cells. Herein, expression of proteins in breast tissues was studied by immunohistochemistry and results were analyzed statistically to obtain semi-quantitative data. Biochemical and functional changes in BAD-overexpressing MCF7 breast cancer cells were evaluated using PCR, reporter assays, western blotting, ELISA and extracellular matrix invasion assays. Compared to normal tissues, Grade II breast cancers expressed low total/phosphorylated forms of BAD in both cytoplasmic and nuclear compartments. BAD overexpression decreasedmore » the expression of β-catenin, Sp1, and phosphorylation of STATs. BAD inhibited Ras/MEK/ERK and JNK signaling pathways, without affecting the p38 signaling pathway. Expression of the metastasis-related proteins, MMP10, VEGF, SNAIL, CXCR4, E-cadherin and TlMP2 was regulated by BAD with concomitant inhibition of extracellular matrix invasion. Inhibition of BAD by siRNA increased invasion and Akt/p-Akt levels. Clinical data and the results herein suggest that in addition to the effect on apoptosis, BAD conveys anti-metastatic effects and is a valuable prognostic marker in breast cancer. - Highlights: • BAD and p-BAD expressions are decreased in breast cancer compared with normal breast tissue. • BAD impedes breast cancer invasion and migration. • BAD inhibits the EMT and transcription factors that promote cancer cell migration. • Invasion and migration functions of BAD are distinct from the BAD's role in apoptosis.« less
  • Here, primary effusion lymphoma (PEL) is a rare large B-cell neoplasm particularly affecting immunodeficient hosts with an increased incidence in young or middle-aged males infected with the HIV. 1 The clinical outcome of patients with PEL is unfavorable with a median survival of <6 months. 1 PEL has been closely associated with human herpes virus 8 (HHV8, previously called Kaposi sarcoma herpesvirus) infection. 1 In some cases a coinfection of HHV8 with the Epstein–Barr Virus (EBV) has been described. 1 HHV8 encodes various genes homologous to cellular genes that have proliferative and anti-apoptotic functions. 2 Although HHV8 is supposed tomore » be a major driver of PEL, it alone is not sufficient for a full-blown lymphomagenesis. 2 PEL usually shows complex karyotypes with many chromosomal aberrations. 3 This chromosomal complexity might be driven by the viral infection and lead to genetic alterations cooperating with HHV8 in PEL lymphomagenesis. 4« less
  • The vaccinia virus O3 protein, a component of the entry–fusion complex, is encoded by all chordopoxviruses. We constructed truncation mutants and demonstrated that the transmembrane domain, which comprises two-thirds of this 35 amino acid protein, is necessary and sufficient for interaction with the entry–fusion complex and function in cell entry. Nevertheless, neither single amino acid substitutions nor alanine scanning mutagenesis revealed essential amino acids within the transmembrane domain. Moreover, replication-competent mutant viruses were generated by randomization of 10 amino acids of the transmembrane domain. Of eight unique viruses, two contained only two amino acids in common with wild type andmore » the remainder contained one or none within the randomized sequence. Although these mutant viruses formed normal size plaques, the entry–fusion complex did not co-purify with the mutant O3 proteins suggesting a less stable interaction. Thus, despite low specific sequence requirements, the transmembrane domain is sufficient for function in entry. - Highlights: • The 35 amino acid O3 protein is required for efficient vaccinia virus entry. • The transmembrane domain of O3 is necessary and sufficient for entry. • Mutagenesis demonstrated extreme sequence flexibility compatible with function.« less
  • Interactions of Bcl-2 family proteins play a regulatory role in mitochondrial apoptosis. The pro-apoptotic protein Bak resides in the outer mitochondrial membrane, and the formation of Bak homo- or heterodimers is involved in the regulation of apoptosis. The previously reported structure of the human Bak protein (residues Glu16-Gly186) revealed that a zinc ion was coordinated with two pairs of Asp160 and His164 residues from the symmetry-related molecules. This zinc-dependent homodimer was regarded as an anti-apoptotic dimer. In the present study, we determined the crystal structure of the human Bak residues Ser23-Asn185 at 2.5 {angstrom}, and found a distinct type ofmore » homodimerization through Cys166 disulfide bridging between the symmetry-related molecules. In the two modes of homodimerization, the molecular interfaces are completely different. In the membrane-targeted model of the S-S bridged dimer, the BH3 motifs are too close to the membrane to interact directly with the anti-apoptotic relatives, such as Bcl-x{sub L}. Therefore, the Bak dimer structure reported here may represent a pro-apoptotic mode under oxidized conditions.« less