Rozanne M. Sandri-Goldin

Ph.D., Johns Hopkins University, 1977

University of California, Irvine
B240B Medical Sciences I
Irvine, CA 92697-4025
(949) 824-7570
Fax (949) 824-9054
rmsandri@uci.edu

UCI Faculty Profile: Rozanne M. Sandri-Goldin

Track Affiliations:
Virology, Mechanisms of Gene Expression, Cell Biology

Research Interests:
Regulatory functions of a post-transcriptionally acting herpesvirus protein; effects of a viral protein on RNA processing pathways and its role in RNA export
 

Herpes simplex virus type 1 (HSV-1) is the prototype and best studied virus of the α-herpesvirus group. HSV-1 is neurotropic and establishes life long latent infections in the sensory neurons of the host. However, it also undergoes a rapid productive replication cycle and is able to infect a wide variety of animals, tissues and cultured cells. A remarkable feature of HSV-1 is the capacity to take over the machinery of the host cell for its own replication during lytic infection. This is a requirement for a nuclear replicating virus that has a rapid and robust replication cycle because the virus must subvert the host cell gene expression program, wherein thousands of mRNAs are transcribed, processed, exported to the cytoplasm and translated. The virus converts the cell into an efficient producer of viral gene products and ultimately, progeny.

 One of the HSV-1 proteins involved in this conversion is the multifunctional protein termed ICP27. The immediate-early (IE) protein, ICP27 is a 63 kDa phosphoprotein that is required for viral replication. ICP27 has a number of effects on gene expression including a contribution to the shut off of host protein synthesis, stimulation of HSV-1 early gene expression, and induction of late viral gene products. It has also been implicated in the repression of host transcription during HSV-1 infection and in the prevention of apoptosis in infected cells. These effects have been shown to occur at both the transcriptional level and post-transcriptionally. While little information has been gathered demonstrating the precise role of ICP27 in the regulation of transcription, we and others have provided evidence that ICP27 functions post-transcriptionally by affecting RNA processing at the level of polyadenylation, splicing, and nucleocytoplasmic export. Specifically, ICP27 stimulates the use of 3’ processing sites in HSV-1 late genes, thus contributing to late viral gene expression. Further, we showed that ICP27 inhibits host cell splicing resulting in the nuclear accumulation of cellular pre-mRNAs and decreased levels of cellular spliced transcripts, thus contributing to the shut-off of host protein synthesis. Finally, we found that export of HSV-1 intronless mRNAs is facilitated by ICP27, which binds HSV-1 transcripts and transports them to the cytoplasm for translation.

In addition to defining the post-transcriptional activities of ICP27, the major focus of my laboratory is to probe the mechanisms by which ICP27 modifies RNA processing and facilitates RNA export. We found that ICP27 acts through protein-protein and protein-RNA interactions. Cellular splicing is inhibited early in infection because ICP27 interacts directly with a number of essential splicing proteins, termed SR proteins, which are required for splicesome assembly. ICP27 alters these proteins by recruiting a predominantly cytoplasmic kinase, SR protein kinase 1 (SRPK1) to the nucleus. SRPK1 is highly specific for arginine-serine dipeptide domains that are the hallmark of SR proteins. The interaction of ICP27 with SRPK1 modifies its activity such that SR proteins are inappropriately phosphorylated impairing their ability to participate in spliceosome assembly, which results in stalled complexes. Splicing of cellular pre-mRNAs is not only required to remove intervening sequences and establish correct coding information, but this process is also required for efficient mRNA export to the cytoplasm. Aly/REF, a cellular export factor, binds to pre-mRNA sites near exon junctions and remains bound to the spliced transcripts to direct them to the TAP(NXF1) nuclear export pathway. Intronless RNAs, which do not associate with spliceosomes, do not come into contact with Aly/REF and are exported less efficiently. We have found that ICP27 binds to Aly/REF and to viral RNAs, allowing HSV-1 intronless transcripts to access the TAP(NXF1) pathway. Thus, the association of ICP27 with splicing complexes not only prevents processing and export of cellular mRNAs but it also provides a means for the efficient export of viral intronless RNAs.

Current research in my laboratory is directed towards elucidating how ICP27 is regulated to perform its varied roles coordinately during viral infection. To this end, we plan to define how ICP27 is directed to sites of RNA processing by determining the nature of the association of ICP27 with RNA polymerase II (RNAP II). We have determined that ICP27 binds, directly or indirectly to the C-terminal domain (CTD) We will also determine if it associates with the initiating or elongating complex; define the region of ICP27 required for interaction with RNAP II; determine if ICP27 binds to the processing factors with which it interacts as part of the RNAP II complex and if ICP27 aids in the recruitment of RNAP II to sites of HSV transcription/replication. In addition, we plan to define the control of HSV-1 RNA export by ICP27 and to define the regulation of ICP27 import/export. We will probe the arginine methylation state of the RGG box of ICP27 and determine if the affinity of ICP27 for Aly/REF or its RNA cargo is enhanced by R-methylation; determine if phosphorylation of ICP27 affects its interaction with Aly/REF; determine the RNA sequence(s) or structures required for ICP27 recognition; define the requirement of RNA binding for ICP27 export, and determine what modifications to ICP27 regulate its import and export cycle. Finally, we plan to initiate structural studies on ICP27 to compare structure and function.

 These studies are important because ICP27 is one of two essential HSV-1 IE proteins and unlike ICP4, which functions in transcription initiation, ICP27 is multifunctional. It appears to be intimately associated with cellular and viral RNA metabolism from transcription and processing through export to the cytoplasm. Determining the mechanisms of its actions and how its diverse functions are coordinately regulated is important for understanding the dynamics of HSV-1 lytic infection and viral take over of the host cell. These studies will also reveal important information about the cellular processes that ICP27 intrudes upon as well. Finally, ICP27 is the only HSV-1 IE protein that has homologues in all of the human herpesviruses and throughout the herpesvirus family. Where studies have been performed on these homologues, functions similar to those that we have described for ICP27 have been found. For example, Epstein-Barr virus (EBV) SM protein has been shown to shuttle between the nucleus and cytoplasm, to mediate the cytoplasmic accumulation of EBV replication gene transcripts, to affect RNA splicing and to associate with an SR protein splicing factor. Other ICP27 homologues have also been shown to function post-transcriptionally. The activities and required domains of ICP27 homologs have only begun to be defined. Our studies will help to elucidate how this intriguing and wide-ranging viral factor orchestrates the subversion of cellular RNA expression pathways to convert them into factories producing viral products.  

UCI Faculty Profile: Rozanne M. Sandri-Goldin.

Selected Publications:

Hardy, W. R. and R. M. Sandri-Goldin. 1994. Herpes simplex virus inhibits host cell splicing and the regulatory protein ICP27 is required for this effect.  J. Virol. 68:7790-7799.

Sandri-Goldin, R. M., M. K. Hibbard and M. A. Hardwicke. 1995. The C-terminal repressor region of herpes simplex virus type 1 ICP27 is required for the redistribution of small nuclear ribonucleoprotein particles and splicing factor SC35, however, these alterations are not sufficient to inhibit host cell splicing.  J. Virol. 69:6063-6076.

Sandri-Goldin, R. M. 1996. Properties and interactions of an HSV-1 immediate early regulatory protein and its effect on host cell splicing. In: Current Developments in Animal Virology, S. Jameel and E.K. Wagner, Eds.  Oxford and IBH Publishing Co., Lebanon, N.H. p. 271-286.

Sandri-Goldin, R. M., and M. K. Hibbard. 1996. The herpes simplex virus type 1 regulatory protein ICP27 coimmunoprecipitates with Anti-Sm antiserum, and the C- terminus appears to be required for this interaction.  J. Virol. 70: 108-118.

Soliman, T.M., R. M. Sandri-Goldin, and S.J. Silverstein. 1997. Shuttling of the herpes simplex virus type 1 regulatory protein ICP27 between the nucleus and cytoplasm mediates the expression of late proteins.  J. Virol. 71:9188-9197.

Sandri-Goldin, R. M. 1998. ICP27 mediates HSV RNA export by shuttling through a leucine-rich nuclear export signal and binding viral intronless RNAs through an RGG motif. Genes Dev.  12:868-879.

Sandri-Goldin, R. M. 1998. Interactions between a herpes simplex virus regulatory protein and cellular mRNA processing pathways.  Methods 16:95-104.

Zhi, Y. and R. M. Sandri-Goldin. 1999. Analysis of the phosphorylation sites of the herpes simplex virus type 1 regulatory protein ICP27. J. Virol. 73:3246-3257.

Zhi, Y., K. S. Sciabica, and R. M. Sandri-Goldin. 1999. Self-interaction of the herpes simplex virus type 1 regulatory protein ICP27.  Virology 257:341-351.

Stingley, S. W., J. J. Garcia Ramirez, S. A. Aguilar, K. Simmen, R. M. Sandri-Goldin, P. H. Ghazal and E. K. Wagner. 2000. Global analysis of HSV type 1 transcription using an oligonucleotide-based DNA microarray.  J. Virol. 74:9916-9927.

Sandri-Goldin, R. M. 2001. Nuclear export of herpes virus RNA. Current Topics in Microbiology and Immunology. 259:2-23.

Chen, I.B., K.S. Sciabica, and R.M. Sandri-Goldin. 2002. ICP27 interacts with the RNA export factor Aly/REF to direct herpes simplex virus type 1 intronless mRNAs to the TAP export pathway. J. Virol.76:12877-12889.

Sciabica, K.S., Q.J. Dai and R. M. Sandri-Goldin. 2003. ICP27 interacts with SRPK1 to mediate HSV splicing inhibition by altering SR protein phosphorylation. EMBO J. 22:1608-1619.

Sandri-Goldin, R.M., 2003. Replication of the herpes simplex virus genome: Does it really go around in circles? Commentary. Proc. Natl. Acad. Sci USA 100:7428-7429

Sandri-Goldin, R.M. 2004. Viral regulators of RNA transport. J. Virol. 78:4389-4396.

Sun, A., G.V. Devi-Rao, M.K. Rice, L.W. Gary, D.C. Bloom, R.M. Sandri-Goldin, P. Ghazal and E.K. Wagner. 2004. Immediate-early expression of the herpes simplex virus type 1 ICP27 transcript is not critical for efficient replication in vivo or in vitro. J. Virol. 78:10470-10478.

Sun A., G. Devi-Rao, M.K. Rice, L.W. Gary, D.C. Bloom, R.M. Sandri-Goldin, P. Gazal  and E.K. Wagner. 2004. The TATGARAT Box of the HSV-1 ICP27 Gene is Essential for Immediate Early Expression but not Critical for Efficient Replication in vitro or in vivo. Virus Genes 29:335-343.

Chen, I. B., L. Li, L. Silva and R.M. Sandri-Goldin. 2005. ICP27 recruits Aly/REF but not TAP/NXF1 to herpes simplex virus type 1 transcription sites although TAP/NXF1 is required for ICP27 export. J. Virol. 79:3949-3961. 

Sandri-Goldin, R.M. Initiation of transcription and RNA synthesis, processing and transport in HSV and VZV infected cells. In Human Herpesviruses: Biology, Therapy and Immunoprophylaxis. Editors: A. Arvin, G. Campadelli-Fiume, P. Moore, E. Mocarski, B. Roizman, R. Whitley and K. Yamanishi. Cambridge University Press. In Press.

Sandri-Goldin, R.M. 2006. RNA Export. In Encyclopedic Reference of Genomics and Proteomics in Molecular Medicine. Editors: K. Ruckpaul and D. Ganten. Springer-Verlag Press. Heidelberg, Germany. DOI 10.1007/3-540-29623-9; 978-3-540-44244-8 (Print) 978-3-540-29623-2 (Online).

Sandri-Goldin, R.M. 2006. The functions and activities of herpes simplex virus protein ICP27, a multifunctional regulator of gene expression. In Alpha Herpesviruses: Molecular and Cellular Biology. Editor: R.M. Sandri-Goldin. Caister Academic Press, Norfolk, U.K.  pp. 65-83.

Dai-Ju, J.Q., L. Li, L.A. Johnson and R.M. Sandri-Goldin. 2006. ICP27 interacts with the C-terminal domain of RNA polymerase II and facilitates its recruitment to herpes simplex virus-1 transcription sites, where it undergoes proteasomal degradation during infection. J. Virol. 80:3567-3581.

Kang, W., R. Mukerjee, J. Gartner, A.G. Hatzeorgiou, R.M. Sandri-Goldin and N.W. Fraser. 2006. Characterization of a spliced exon product of a herpes simplex type-1 latency associated transcript in productively infected cells. Virology 356(1-2):106-114.

List of Publications via PubMed (NIH National Library of Medicine)