Characterization of the role of adenovirus-5 (Ad-5) gene products E2A, E4ORF6 and VA RNA on adeno-associated virus type 5 (AAV5) transcription, translation and replication

2007 ◽  
Author(s):  
Ramnath Nayak
Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 989-989 ◽  
Author(s):  
Abdullah M. Ali ◽  
Thiyam R. Singh ◽  
Ruhikanta A. Meetei

Abstract Fanconi Anemia (FA) is an autosomal recessive and X-linked disorder characterized by congenital abnormalities, progressive bone marrow failure, and a high incidence of hematological (acute leukemia) and non-hematological malignancies (squamous cell carcinomas of the head and neck or gynecologic system). FA is genetically heterogeneous disease and to date 12 complementation groups are known of which 11 gene products have been identified (FANC- A, B, C, D1, D2, E, F, G, J, L, M). Eight of the FA gene products, FANCA, FANCB, FANC, FANCE, FANCF, FANCG, FANCL and FANCM form a multiprotein FA core complex. This complex is required for the monoubiquitination of FANCD2 upon DNA damage by various genotoxic agents. The other two FA proteins; FANCD1/BRCA2 and FANCJ are believed to act “downstream” of FANCD2. In order to understand the role of FA proteins in DNA repair pathway it is necessary to find all the FA genes and their interacting partners. We have established a two-step purification method using 6XHis and FLAG tags for the biochemical and functional characterization of the FA core complex proteins. In an attempt to isolate interacting partners of FANCM and FANCL proteins; we have established two different HeLa cell lines; HeLa-HF-FANCM and HeLa-HF-FANCL, stably expressing HF-FANCM and HF-FANCL recombinant proteins respectively. Two step affinity purification was carried out to isolate the complexes from the extracts prepared from stable cell lines. Two polypeptides, namely, FAAP16 and FAAP100 were identified by mass-spectrometry as major interacting partners of FANCM and FANCL respectively. The interaction of FAAP16 and FAAP100 with other FA core complex proteins was confirmed by reciprocal affinity purification coupled mass-spectrometry using HeLa cells stably expressing HF-FAAP16 and HF-FAAP100 proteins. Furthermore, suppression of FAAP16 and FAAP100 in HeLa cells using siRNA resulted in a reduced MMC-induced FANCD2 monoubiquitination. Studies are being carried out to understand the precise role of these proteins in the FA core complex. These data suggest additional proteins interact with FA core complex members and demonstrate the utility of the purification method in delineating interacting proteins involved in FA.


2006 ◽  
Vol 81 (4) ◽  
pp. 2069-2073 ◽  
Author(s):  
Changchun Ren ◽  
April F. White ◽  
Selvarangan Ponnazhagan

ABSTRACT We report here the significance of the Notch1 receptor in intracellular trafficking of recombinant adeno-associated virus type 2 (rAAV2). RNA profiling of human prostate cancer cell lines with various degrees of AAV transduction indicated a correlation of the amount of Notch1 with rAAV transgene expression. A definitive role of Notch1 in enhancing AAV transduction was confirmed by developing clonal derivatives of DU145 cells overexpressing either full-length or intracellular Notch1. To discern stages of AAV2 transduction influenced by Notch1, competitive binding with soluble heparin and Notch1 antibody, intracellular trafficking using Cy3-labeled rAAV2, and blocking assays for proteasome and dynamin pathways were performed. Results indicated that in the absence or low-level expression of Notch1, only binding of virus was found on the cell surface and internalization was impaired. However, increased Notch1 expression in these cells allowed efficient perinuclear accumulation of labeled capsids. Nuclear transport of the vector was evident by transgene expression and real-time PCR analyses. Dynamin levels were not found to be different among these cell lines, but blocking dynamin function abrogated AAV2 transduction in DU145 clones overexpressing full-length Notch1 but not in clones overexpressing intracellular Notch1. These studies provide evidence for the role of activated Notch1 in intracellular trafficking of AAV2, which may have implications in the optimal use of AAV2 in human gene therapy.


Virology ◽  
1977 ◽  
Vol 82 (1) ◽  
pp. 84-92 ◽  
Author(s):  
Hiroshi Handa ◽  
Kazuko Shiroki ◽  
Hiroto Shimojo

1999 ◽  
Vol 73 (2) ◽  
pp. 1309-1319 ◽  
Author(s):  
John A. Chiorini ◽  
Frank Kim ◽  
Linda Yang ◽  
Robert M. Kotin

ABSTRACT Adeno-associated virus type 5 (AAV5) is distinct from other dependovirus serotypes based on DNA hybridization and serological data. To better understand the biology of AAV5, we have cloned and sequenced its genome and generated recombinant AAV5 particles. The single-stranded DNA genome is similar in length and genetic organization to that of AAV2. The rep gene of AAV5 is 67% homologous to AAV2, with the majority of the changes occurring in the carboxyl and amino termini. This homology is much less than that observed with other reported AAV serotypes. The inverted terminal repeats (ITRs) are also unique compared to those of the other AAV serotypes. While the characteristic AAV hairpin structure and the Rep DNA binding site are retained, the consensus terminal resolution site is absent. These differences in the Rep proteins and the ITRs result in a lack of cross-complementation between AAV2 and AAV5 as measured by the production of recombinant AAV particles. Alignment of the cap open reading frame with that of the other AAV serotypes identifies both conserved and variable regions which could affect tissue tropism and particle stability. Comparison of transduction efficiencies in a variety of cells lines and a lack of inhibition by soluble heparin indicate that AAV5 may utilize a distinct mechanism of uptake compared to AAV2.


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