Masahiko Kobayashi

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DNA replication stress triggers the activation of Checkpoint Kinase 1 (Chk1) in a pathway that requires the independent chromatin loading of the ATRIP-ATR (ATR-interacting protein/ATM [ataxia-telangiectasia mutated]-Rad3-related kinase) complex and the Rad9-Hus1-Rad1 (9-1-1) clamp. We show that Rad9's role in Chk1 activation is to bind TopBP1, which(More)
The ubiquitin (Ub)-conjugating enzyme Ubc13 is implicated in Rad6/Rad18-dependent postreplication repair (PRR) in budding yeast, but its function in vertebrates is not known. We show here that disruption or siRNA depletion of UBC13 in chicken DT40 or human cells confers severe growth defects due to chromosome instability, and hypersensitivity to both UV and(More)
Gene polymorphisms of the UDP-glucuronosyltransferase 1 family, polypeptide A1 (UGT1A1) contribute to individual variations in adverse events among patients administered irinotecan, and the distribution of the polymorphisms shows large interethnic differences. Variation in the solute carrier organic anion-transporter family, member 1B1 (SLCO1B1) gene also(More)
OBJECTIVE To determine whether interleukin-1 (IL-1) or tumor necrosis factor alpha (TNFalpha), or both, plays a role in the excessive degradation that is observed in cultured osteoarthritic (OA) articular cartilage. METHODS Antagonists of IL-1 and TNFalpha, namely, IL-1 receptor antagonist and the PEGylated soluble TNFalpha receptor I, respectively, were(More)
Enhanced locomotory activity (ELA), such as wandering, is a normal behavior that occurs at the end of the larval stage in lepidopteran (butterflies and moths) insects. Baculovirus infection can also induce ELA in lepidopteran larvae. The belief is that the virus induces this behavior to increase its transmission [Goulson, D. (1997) Oecologia 109, 219-228].(More)
We identified a novel, 6,513-bp-long RNA, termed Bombyx mori macula-like latent virus (BmMLV) RNA, which abundantly expressed in B. mori cultured BmN cells. BmMLV RNA potentially encodes two proteins, putative RNA replicase and coat protein, which share structural features and sequence similarities with those of a plant RNA virus, the genus Maculavirus.(More)
In Bombyx mori, the female is the heterogametic sex and the sex determining system is referred to as ZZ/ZW. In a previous study, we found that this insect does not show dosage compensation at the transcriptional level. To confirm the validity of our conclusion, we investigated whether or not another sex-linked gene is dosage compensated. To identify new(More)
We evaluated the techniques of colonic interposition and supercharge for esophageal reconstruction and discussed the main considerations related to these procedures. In this study, we performed 51 esophageal reconstructions using colonic interposition. Twenty-eight of the 51 patients had synchronous or allochronic gastric malignancy. We selected colonic(More)
The purpose of this study was to examine the effect of deep flexion on the long-term durability of a high-flex ceramic implant in total knee arthroplasty. Five hundred and five consecutive knees replaced with a Bi-Surface knee system (Kyocera Medical, Osaka, Japan) were divided into two groups according to the range of flexion by 135° postoperatively.(More)
Zn²(+)-finger proteins comprise one of the largest protein superfamilies with diverse biological functions. The ATM substrate Chk2-interacting Zn²(+)-finger protein (ASCIZ; also known as ATMIN and ZNF822) was originally linked to functions in the DNA base damage response and has also been proposed to be an essential cofactor of the ATM kinase. Here we show(More)