Chie Izumiya

Kaposi s sarcoma-associated herpesvirus-encoded protein kinase and its interaction with K-bZIP

Published in Journal of Virology

Kaposi s sarcoma-associated herpesvirus K-Rta exhibits SUMO-targeting ubiquitin ligase (STUbL) like activity and is esse...

Published in PLoS Pathogens

The small ubiquitin-like modifier (SUMO) is a protein that regulates a wide variety of cellular processes by covalent attachment of SUMO moieties to a diverse array of target proteins. Sumoylation also plays an important role in the replication of many viruses. Previously, we showed that Kaposi s sarcoma-associated herpesvirus (KSHV) encodes a SUMO...

Protein arginine methyltransferase 1-directed methylation of Kaposi sarcoma-associated herpesvirus latency-associated nu...

Published in Journal of Biological Chemistry

The Kaposi sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen (LANA) is a multifunctional protein with roles in gene regulation and maintenance of viral latency. Post-translational modification of LANA is important for functional diversification. Here, we report that LANA is subject to arginine methylation by protein arginine ...

NF-kappaB serves as a cellular sensor of Kaposi s sarcoma-associated herpesvirus latency and negatively regulates K-Rta ...

Published in Journal of Virology

Successful viral replication is dependent on a conducive cellular environment; thus, viruses must be sensitive to the state of their host cells. We examined the idea that an interplay between viral and cellular regulatory factors determines the switch from Kaposi s sarcoma-associated herpesvirus (KSHV) latency to lytic replication. The immediate-ea...

A lytic viral long noncoding RNA modulates the function of a latent protein.

Published in Journal of Virology

Latent Kaposi s sarcoma-associated herpesvirus (KSHV) episomes are coated with viral latency-associated nuclear antigen (LANA). In contrast, LANA rapidly disassociates from episomes during reactivation. Lytic KSHV expresses polyadenylated nuclear RNA (PAN RNA), a long noncoding RNA (lncRNA). We report that PAN RNA promotes LANA-episome disassociati...

Cell cycle regulation by Kaposi s sarcoma-associated herpesvirus K-bZIP: direct interaction with cyclin-CDK2 and inducti...

Published in Journal of Virology

In order to cope with hostile host environments, many viruses have developed strategies to perturb the cellular machinery to suit their replication needs. Some herpesvirus genes protect cells from undergoing apoptosis to prolong the lives of infected cells, while others, such as Epstein-Barr virus Zta, slow down the G(1)/S transition phase to allow...

Kaposi s sarcoma-associated herpesvirus K-bZIP is a coregulator of K-Rta: physical association and promoter-dependent tr...

Published in Journal of Virology

Kaposi s sarcoma-associated herpesvirus (KSHV) is a human gammaherpesvirus that has been implicated in the pathogenesis of Kaposi s sarcoma and B-cell neoplasms. The genomic organization of KSHV is similar to that of Epstein-Barr virus (EBV). EBV encodes two transcriptional factors, Rta and Zta, which functionally interact to transactivate EBV gene...

PRMT4-mediated arginine methylation negatively regulates retinoblastoma tumor suppressor protein and promotes E2F-1 diss...

Published in Molecular and Cellular Biology

The retinoblastoma protein (pRb/p105) tumor suppressor plays a pivotal role in cell cycle regulation by blockage of the G1-to-S-phase transition. pRb tumor suppressor activity is governed by a variety of posttranslational modifications, most notably phosphorylation by cyclin-dependent kinase (Cdk) complexes. Here we report a novel regulation of pRb...

KDM8, a H3K36me2 histone demethylase that acts in the cyclin A1 coding region to regulate cancer cell proliferation.

Published in Proceedings of the National Academy of Sciences

Localized chromatin modifications of histone tails play an important role in regulating gene transcription, and aberration of these processes leads to carcinogenesis. Methylated histone lysine residues, a key player in chromatin remodeling, are demethylated by the JmjC class of enzymes. Here we show that JMJD5 (now renamed KDM8), a JmjC family memb...

Kaposi s sarcoma-associated herpesvirus (KSHV) latency-associated nuclear antigen regulates the KSHV epigenome by associ...

Published in Journal of Virology

Kaposi s sarcoma-associated herpesvirus (KSHV) latent genomes are tethered to host histones to form a minichromosome also known as an "episome." Histones, which are core components of chromatin, are heavily modified by various histone-targeting enzymes. Posttranslational modifications of histones significantly influence accessibility of transcripti...