Our Technophile
Soumeya Jaballah
Postdoctoral Fellow
Dr. Jaballah recently joined as a postdoctoral fellow after obtaining her PhD from the School of Biological Sciences, University of Auckland, New Zealand. During her PhD, she worked on the structural and functional analysis of a retroviral Gag polyprotein. In her new role as a postdoctoral fellow, Dr. Jaballah will be working towards developing the next generation of retroviral vectors and packaging cell lines and test their ability to reverse single gene disorders in animal model systems.
E-mail: [email protected]; [email protected]
Publications
2017
SA, Jaballah; GD, Bailey; A, Desfosses; J, Hyun; AK, Mitra; RL, Kingston
In vitro assembly of the Rous Sarcoma Virus capsid protein into hexamer tubes at physiological temperature Journal Article
In: Scientific reports, vol. 7, no. 1, 2017, ISSN: 2045-2322.
@article{RN154,
title = {In vitro assembly of the Rous Sarcoma Virus capsid protein into hexamer tubes at physiological temperature},
author = {Jaballah SA and Bailey GD and Desfosses A and Hyun J and Mitra AK and Kingston RL},
url = {https://www.ncbi.nlm.nih.gov/pubmed/28588198},
doi = {10.1038/s41598-017-02060-0},
issn = {2045-2322},
year = {2017},
date = {2017-01-01},
journal = {Scientific reports},
volume = {7},
number = {1},
abstract = {During a proteolytically-driven maturation process, the orthoretroviral capsid protein (CA) assembles to form the convex shell that surrounds the viral genome. In some orthoretroviruses, including Rous Sarcoma Virus (RSV), CA carries a short and hydrophobic spacer peptide (SP) at its C-terminus earl …},
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pubstate = {published},
tppubtype = {article}
}
During a proteolytically-driven maturation process, the orthoretroviral capsid protein (CA) assembles to form the convex shell that surrounds the viral genome. In some orthoretroviruses, including Rous Sarcoma Virus (RSV), CA carries a short and hydrophobic spacer peptide (SP) at its C-terminus earl …
2010
Jaballah, S. A.; Aktar, S. J.; Ali, J.; Phillip, P. S.; Dhaheri, N. S. Al; Jabeen, A.; Rizvi, T. A.
In: J Mol Biol, vol. 401, no. 5, pp. 996-1014, 2010, ISSN: 0022-2836.
@article{RN42,
title = {A G-C-rich palindromic structural motif and a stretch of single-stranded purines are required for optimal packaging of Mason-Pfizer monkey virus (MPMV) genomic RNA},
author = {S. A. Jaballah and S. J. Aktar and J. Ali and P. S. Phillip and N. S. Al Dhaheri and A. Jabeen and T. A. Rizvi},
doi = {10.1016/j.jmb.2010.06.043},
issn = {0022-2836},
year = {2010},
date = {2010-01-01},
urldate = {2010-01-01},
journal = {J Mol Biol},
volume = {401},
number = {5},
pages = {996-1014},
abstract = {During retroviral RNA packaging, two copies of genomic RNA are preferentially packaged into the budding virus particles whereas the spliced viral RNAs and the cellular RNAs are excluded during this process. Specificity towards retroviral RNA packaging is dependent upon sequences at the 5' end of the viral genome, which at times extend into Gag sequences. It has earlier been suggested that the Mason-Pfizer monkey virus (MPMV) contains packaging sequences within the 5' untranslated region (UTR) and Gag. These studies have also suggested that the packaging determinants of MPMV that lie in the UTR are bipartite and are divided into two regions both upstream and downstream of the major splice donor. However, the precise boundaries of these discontinuous regions within the UTR and the role of the intervening sequences between these dipartite sequences towards MPMV packaging have not been investigated. Employing a combination of genetic and structural prediction analyses, we have shown that region "A", immediately downstream of the primer binding site, is composed of 50 nt, whereas region "B" is composed of the last 23 nt of UTR, and the intervening 55 nt between these two discontinuous regions do not contribute towards MPMV RNA packaging. In addition, we have identified a 14-nt G-C-rich palindromic sequence (with 100% autocomplementarity) within region A that has been predicted to fold into a structural motif and is essential for optimal MPMV RNA packaging. Furthermore, we have also identified a stretch of single-stranded purines (ssPurines) within the UTR and 8 nt of these ssPurines are duplicated in region B. The native ssPurines or its repeat in region B when predicted to refold as ssPurines has been shown to be essential for RNA packaging, possibly functioning as a potential nucleocapsid binding site. Findings from this study should enhance our understanding of the steps involved in MPMV replication including RNA encapsidation process.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
During retroviral RNA packaging, two copies of genomic RNA are preferentially packaged into the budding virus particles whereas the spliced viral RNAs and the cellular RNAs are excluded during this process. Specificity towards retroviral RNA packaging is dependent upon sequences at the 5' end of the viral genome, which at times extend into Gag sequences. It has earlier been suggested that the Mason-Pfizer monkey virus (MPMV) contains packaging sequences within the 5' untranslated region (UTR) and Gag. These studies have also suggested that the packaging determinants of MPMV that lie in the UTR are bipartite and are divided into two regions both upstream and downstream of the major splice donor. However, the precise boundaries of these discontinuous regions within the UTR and the role of the intervening sequences between these dipartite sequences towards MPMV packaging have not been investigated. Employing a combination of genetic and structural prediction analyses, we have shown that region "A", immediately downstream of the primer binding site, is composed of 50 nt, whereas region "B" is composed of the last 23 nt of UTR, and the intervening 55 nt between these two discontinuous regions do not contribute towards MPMV RNA packaging. In addition, we have identified a 14-nt G-C-rich palindromic sequence (with 100% autocomplementarity) within region A that has been predicted to fold into a structural motif and is essential for optimal MPMV RNA packaging. Furthermore, we have also identified a stretch of single-stranded purines (ssPurines) within the UTR and 8 nt of these ssPurines are duplicated in region B. The native ssPurines or its repeat in region B when predicted to refold as ssPurines has been shown to be essential for RNA packaging, possibly functioning as a potential nucleocapsid binding site. Findings from this study should enhance our understanding of the steps involved in MPMV replication including RNA encapsidation process.
2009
Dhaheri, N. S. Al; Phillip, P. S.; Ghazawi, A.; Ali, J.; Beebi, E.; Jaballah, S. A.; Rizvi, T. A.
Cross-packaging of genetically distinct mouse and primate retroviral RNAs Journal Article
In: Retrovirology, vol. 6, pp. 66, 2009, ISSN: 1742-4690.
@article{RN66,
title = {Cross-packaging of genetically distinct mouse and primate retroviral RNAs},
author = {N. S. Al Dhaheri and P. S. Phillip and A. Ghazawi and J. Ali and E. Beebi and S. A. Jaballah and T. A. Rizvi},
doi = {10.1186/1742-4690-6-66},
issn = {1742-4690},
year = {2009},
date = {2009-01-01},
urldate = {2009-01-01},
journal = {Retrovirology},
volume = {6},
pages = {66},
abstract = {BACKGROUND: The mouse mammary tumor virus (MMTV) is unique from other retroviruses in having multiple viral promoters, which can be regulated by hormones in a tissue specific manner. This unique property has lead to increased interest in studying MMTV replication with the hope of developing MMTV based vectors for human gene therapy. However, it has recently been reported that related as well as unrelated retroviruses can cross-package each other's genome raising safety concerns towards the use of candidate retroviral vectors for human gene therapy. Therefore, using a trans complementation assay, we looked at the ability of MMTV RNA to be cross-packaged and propagated by an unrelated primate Mason-Pfizer monkey virus (MPMV) that has intracellular assembly process similar to that of MMTV. RESULTS: Our results revealed that MMTV and MPMV RNAs could be cross-packaged by the heterologous virus particles reciprocally suggesting that pseudotyping between two genetically distinct retroviruses can take place at the RNA level. However, the cross-packaged RNAs could not be propagated further indicating a block at post-packaging events in the retroviral life cycle. To further confirm that the specificity of cross-packaging was conferred by the packaging sequences (psi), we cloned the packaging sequences of these viruses on expression plasmids that generated non-viral RNAs. Test of these non-viral RNAs confirmed that the reciprocal cross-packaging was primarily due to the recognition of psi by the heterologous virus proteins. CONCLUSION: The results presented in this study strongly argue that MPMV and MMTV are promiscuous in their ability to cross-package each other's genome suggesting potential RNA-protein interactions among divergent retroviral RNAs proposing that these interactions are more complicated than originally thought. Furthermore, these observations raise the possibility that MMTV and MPMV genomes could also co-package providing substrates for exchanging genetic information.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
BACKGROUND: The mouse mammary tumor virus (MMTV) is unique from other retroviruses in having multiple viral promoters, which can be regulated by hormones in a tissue specific manner. This unique property has lead to increased interest in studying MMTV replication with the hope of developing MMTV based vectors for human gene therapy. However, it has recently been reported that related as well as unrelated retroviruses can cross-package each other's genome raising safety concerns towards the use of candidate retroviral vectors for human gene therapy. Therefore, using a trans complementation assay, we looked at the ability of MMTV RNA to be cross-packaged and propagated by an unrelated primate Mason-Pfizer monkey virus (MPMV) that has intracellular assembly process similar to that of MMTV. RESULTS: Our results revealed that MMTV and MPMV RNAs could be cross-packaged by the heterologous virus particles reciprocally suggesting that pseudotyping between two genetically distinct retroviruses can take place at the RNA level. However, the cross-packaged RNAs could not be propagated further indicating a block at post-packaging events in the retroviral life cycle. To further confirm that the specificity of cross-packaging was conferred by the packaging sequences (psi), we cloned the packaging sequences of these viruses on expression plasmids that generated non-viral RNAs. Test of these non-viral RNAs confirmed that the reciprocal cross-packaging was primarily due to the recognition of psi by the heterologous virus proteins. CONCLUSION: The results presented in this study strongly argue that MPMV and MMTV are promiscuous in their ability to cross-package each other's genome suggesting potential RNA-protein interactions among divergent retroviral RNAs proposing that these interactions are more complicated than originally thought. Furthermore, these observations raise the possibility that MMTV and MPMV genomes could also co-package providing substrates for exchanging genetic information.