Jaehoon Kim

Recent yeast genetic studies have implicated the ubiquitin-conjugating enzyme and ubiquitin ligase functions of yRad6 and yBre1, respectively, in H2B ubiquitylation. However, there have been no corresponding biochemical analyses demonstrating intrinsic enzyme activities of yRad6 and yBre1 or related mechanistic details. Here, we describe a robust in vitro chromatin ubiquitylation assay that involves purified H2B ubiquitylation factors and natural nucleosomes. Our results indicate that yRad6 has

We have identified a novel DNA helicase in humans that belongs to members of the superfamily I helicase and found that it contains a well conserved F-box motif at its N terminus. We have named the enzyme hFBH1 (human F-box DNA helicase 1). Recombinant hFBH1, containing glutathione S-transferase at the N terminus, was expressed in Sf9 cells and purified. In this report, we show that hFBH1 exhibited DNA-dependent ATPase and DNA unwinding activities that displace duplex DNA in the 3' to 5' directio

In mammalian cells, distinct H3K4 methylation states are created by deposition of methyl groups by multiple complexes of histone lysine methyltransferase 2 (KMT2) family proteins. For comprehensive analyses that directly compare the catalytic properties of all six human KMT2 complexes, we employed a biochemically defined system reconstituted with recombinant KMT2 core complexes (KMT2CoreCs) containing minimal components required for nucleosomal H3K4 methylation activity. We found that each KMT2C

RNF40 (OMIM: 607700) is a really interesting new gene (RING) finger E3 ubiquitin ligase containing multiple coiled-coil domains and a C-terminal RING finger motif, which engage in protein-DNA and protein-protein interactions. RNF40 encodes a polypeptide of 1001 amino acids with a predicted molecular mass of 113,678 Da. RNF40 and its paralog RNF20 form a stable heterodimer complex that can monoubiquitylate histone H2B at lysine 120 as well as other nonhistone proteins. Cancer is a major public he

Rubicon is part of a Beclin-1-Vps34-containing autophagy complex. Rubicon induces antimicrobial responses upon Toll-like receptor (TLR) stimulation and functions as a feedback inhibitor to prevent unbalanced proinflammatory responses depending on dectin-1 signaling. However, the role played by Rubicon during antiviral immune responses, particularly the type I interferon (IFN) responses, remains largely unknown. Here, we report that Rubicon acts as a negative regulator for virus-triggered IFN sig

FAS-associated factor-1 (FAF1) is a component of the death-inducing signaling complex involved in Fas-mediated apoptosis. It regulates NF-κB activity, ubiquitination, and proteasomal degradation. Here, we found that FAF1 positively regulates the type I interferon pathway. FAF1gt/gt mice, which deficient in FAF1, and FAF1 knockdown immune cells were highly susceptible to RNA virus infection and showed low levels of inflammatory cytokines and type I interferon (IFN) production. FAF1 was bound comp

Replication fork reversal is one of the major pathways for reactivating stalled DNA replication. Many enzymes with replication fork reversal activity have DNA-unwinding activity as well, but none of the fork reversal enzymes in the SWI/SNF family shows a separate DNA-unwinding activity, raising the question of how they initiate the remodeling process. Here, we found ATP binding to Rad5 induces the unwinding of the leading arm of the replication fork and proximally positions the leading and laggi

The human genome encodes large numbers of non-coding RNAs, including divergent antisense transcripts at transcription start sites (TSSs). However, molecular mechanisms by which divergent antisense transcription is regulated have not been detailed. Here, we report a novel ZWC complex composed of ZC3H4, WDR82 and CK2 that suppresses divergent antisense transcription. The ZWC complex preferentially localizes at TSSs of active genes through direct interactions of ZC3H4 and WDR82 subunits with the S5