Stability of a Long Noncoding Viral RNA Depends on a 9-Nt Core Element at the RNA 5' End to Interact with Viral ORF57 and Cellular PABPC1

Massimelli, María J.; Kang, Jeong-Gu; Majerčiak, Vladimır; Le, Shu-Yun; Liewehr, David J.; Steinberg, Seth M.; Zheng, Zhi-Ming

doi:10.7150/ijbs.7.1145

Cited by 72 publications

(173 citation statements)

References 58 publications

Supporting

Mentioning

158

Contrasting

Order By: Relevance

“…PAN RNA contains an ORF57-responsive element (ORE) in its 5=-most 300 nucleotides (nt) that is sufficient for ORF57 binding (50,63,66). In addition, deletion of this element from PAN RNA dramatically decreases the efficiency of ORF57 binding to PAN RNA.…”

Section: Refmentioning

confidence: 99%

Viral Factors Reveal a Role for REF/Aly in Nuclear RNA Stability

Stubbs

Hunter

Hoover

et al. 2012

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

Section: Refmentioning

confidence: 99%

Viral Factors Reveal a Role for REF/Aly in Nuclear RNA Stability

Stubbs

Hunter

Hoover

et al. 2012

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

“…Mammalian expression vectors pVM7 for FLAGtagged ORF57, pVM68 for 3ϫ FLAG-tagged ORF57, pJM1 for PAN RNA, pJM5 for K5, and pJM6 for viral G-protein-coupled receptor (vGPCR) were described in our previous reports (47,51,58). PABPC1-myc-expressing plasmid was purchased from Origene (Rockville, MD).…”

Section: Cells Jsc-1 Cells (Kshv Positive [Kshvmentioning

confidence: 99%

“…It is now recognized that PAN is a regulatory lncRNA important for viral gene expression, replication, and immune modulation (53)(54)(55). The observation that KSHV ORF57, PABPC1, and E1B-AP5 interact with the PAN 5=-end motif (51) highlights the importance of these new discoveries regarding the nuclear accumulation and function of PAN RNA during KSHV lytic infection. In this study, we demonstrate that PABPC1 directly interacts with the 9-nt core in MRE stemloop II (MRE-II) at the PAN 5= end and this interaction is necessary for ORF57 association with the MRE core.…”

mentioning

confidence: 99%

“…We and others recently described the ORF57-mediated nuclear accumulation and stability of a KSHV long noncoding RNA (lncRNA), polyadenylated nuclear (PAN) RNA, by ORF57 interacting with an Mta-responsive element (MRE) containing a 9-nucleotide (nt) core at the 5= end of PAN RNA (51,52). The MRE at the 5= PAN also interacts with PABPC1 and a heterogeneous nuclear ribonucleoprotein Ulike 1 (hnRNPUL1 or E1B-AP5 [E1B 55-kilodalton-associated protein 5]) (51). It has been shown that the binding of nuclear PABPC1 to the poly(A) tail of PAN is required for SOX-mediated accumulation of nuclear PAN (28,53).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Interplay between Polyadenylate-Binding Protein 1 and Kaposi's Sarcoma-Associated Herpesvirus ORF57 in Accumulation of Polyadenylated Nuclear RNA, a Viral Long Noncoding RNA

Massimelli

Majerčiak

Kruhlak

et al. 2013

J Virol

Self Cite

View full text Add to dashboard Cite

Polyadenylate-binding protein cytoplasmic 1 (PABPC1) is a cytoplasmic-nuclear shuttling protein important for protein translation initiation and both RNA processing and stability. We report that PABPC1 forms a complex with the Kaposi's sarcomaassociated herpesvirus (KSHV) ORF57 protein, which allows ORF57 to interact with a 9-nucleotide (nt) core element of KSHV polyadenylated nuclear (PAN) RNA, a viral long noncoding RNA (lncRNA), and increase PAN stability. The N-terminal RNA recognition motifs (RRMs) of PABPC1 are necessary for the direct interaction with ORF57. During KSHV lytic infection, the expression of viral ORF57 leads to a substantial decrease in overall PABPC1 expression, along with a shift in the cellular distribution of the remaining PABPC1 to the nucleus. Interestingly, PABPC1 and ORF57 have opposing functions in modulating PAN steady-state accumulation. The suppressive effect of PABPC1 specific to PAN expression is alleviated by small interfering RNA knockdown of PABPC1 or by overexpression of ORF57. Conversely, ectopic PABPC1 reduces ORF57 steady-state protein levels and induces aberrant polyadenylation of PAN and thereby indirectly inhibits ORF57-mediated PAN accumulation. However, E1B-AP5 (heterogeneous nuclear ribonucleoprotein U-like 1), which interacts with a region outside the 9-nt core to stimulate PAN expression, does not interact or even colocalize with ORF57. Unlike PABPC1, the nuclear distribution of E1B-AP5 remains unchanged by viral lytic infection or overexpression of ORF57. Together, these data indicate that PABPC1 is an important cellular target of viral ORF57 to directly upregulate PAN accumulation during viral lytic infection, and the ability of host PABPC1 to disrupt ORF57 expression is a strategic host counterbalancing mechanism.

show abstract

“…aposi's sarcoma-associated herpesvirus (KSHV) ORF57 (also known as Mta) is expressed early in the KSHV lytic cycle and is required for the efficient expression of a subset of viral genes, including KSHV PAN, ORF59, K8, viral interleukin-6 (vIL-6), ORF47, and others (1)(2)(3)(4)(5)(6)(7). A KSHV genome lacking ORF57 expression is associated with a defective lytic cycle incapable of producing infectious virions (8,9).…”

mentioning

confidence: 99%

Stability of Structured Kaposi's Sarcoma-Associated Herpesvirus ORF57 Protein Is Regulated by Protein Phosphorylation and Homodimerization

Majerčiak

Pripuzova

Chan

et al. 2015

J Virol

Self Cite

View full text Add to dashboard Cite

Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 plays an essential role in KSHV lytic infection by promoting viral gene expression at the posttranscriptional level. Using bioinformatic and biochemical approaches, we determined that ORF57 contains two structurally and functionally distinct domains: a disordered nonstructural N-terminal domain (amino acids [aa] 1 to 152) and a structured ␣-helix-rich C-terminal domain (aa 153 to 455). The N-terminal domain mediates ORF57 interaction with several RNA-protein complexes essential for ORF57 to function. The N-terminal phosphorylation by cellular casein kinase II (CKII) at S21, T32, and S43, and other cellular kinases at S95 and S97 residues in proximity of the caspase-7 cleavage site, 30-DETD-33, inhibits caspase-7 digestion of ORF57. The structured C-terminal domain mediates homodimerization of ORF57, and the critical region for this function was mapped carefully to ␣-helices 7 to 9. Introduction of point mutations into ␣-helix 7 at ORF57 aa 280 to 299, a region highly conserved among ORF57 homologues from other herpesviruses, inhibited ORF57 homodimerization and led to proteasome-mediated degradation of ORF57 protein. Thus, homodimerization of ORF57 via its C terminus prevents ORF57 from degrading and allows two structure-free N termini of the dimerized ORF57 to work coordinately for host factor interactions, leading to productive KSHV lytic infection and pathogenesis. IMPORTANCEKSHV is a human oncogenic virus linked to the development of several malignancies. KSHV-mediated oncogenesis requires both latent and lytic infection. The KSHV ORF57 protein is essential for KSHV lytic replication, as it regulates the expression of viral lytic genes at the posttranscriptional level. This report provides evidence that the structural conformation of the ORF57 protein plays a critical role in regulation of ORF57 stability. Phosphorylation by CKII on the identified serine/threonine residues at the N-terminal unstructured domain of ORF57 prevents its digestion by caspase-7. The C-terminal domain of ORF57, which is rich in ␣-helices, contributes to homodimerization of ORF57 to prevent proteasome-mediated protein degradation. Elucidation of the ORF57 structure not only enables us to better understand ORF57 stability and functions but also provides an important tool for us to modulate ORF57's activity with the aim to inhibit KSHV lytic replication. K aposi's sarcoma-associated herpesvirus (KSHV) ORF57 (also known as Mta) is expressed early in the KSHV lytic cycle and is required for the efficient expression of a subset of viral genes, including KSHV PAN, ORF59, K8, viral interleukin-6 (vIL-6), ORF47, and others (1-7). A KSHV genome lacking ORF57 expression is associated with a defective lytic cycle incapable of producing infectious virions (8, 9).KSHV ORF57 functions as a posttranscriptional regulator of viral gene expression by affecting RNA stability (PAN, ORF59, and ORF47), splicing (ORF50 and K8), polyadenylation (ORF59), and translation (vIL-6) (1, 2, 4-7, 10) but ...

show abstract

Stability of a Long Noncoding Viral RNA Depends on a 9-Nt Core Element at the RNA 5' End to Interact with Viral ORF57 and Cellular PABPC1

Cited by 72 publications

References 58 publications

Viral Factors Reveal a Role for REF/Aly in Nuclear RNA Stability

Viral Factors Reveal a Role for REF/Aly in Nuclear RNA Stability

Interplay between Polyadenylate-Binding Protein 1 and Kaposi's Sarcoma-Associated Herpesvirus ORF57 in Accumulation of Polyadenylated Nuclear RNA, a Viral Long Noncoding RNA

Stability of Structured Kaposi's Sarcoma-Associated Herpesvirus ORF57 Protein Is Regulated by Protein Phosphorylation and Homodimerization

Contact Info

Product

Resources

About