Osaka University

About: Osaka University is a education organization based out in Osaka, Japan. It is known for research contribution in the topics: Laser & Catalysis. The organization has 83778 authors who have published 185669 publications receiving 5158122 citations. The organization is also known as: Ōsaka daigaku.

Role of Bcl-2 family proteins in apoptosis: apoptosomes or mitochondria?

Abstract: Apoptosis is an essential physiological process for the selective elimination of cells, which is involved in a variety of biological events. The Bcl-2 family is the best characterized protein family involved in the regulation of apoptotic cell death, consisting of anti-apoptotic and pro-apoptotic members. The anti-apoptotic members of this family, such as Bcl-2 and Bcl-XL, prevent apoptosis either by sequestering proforms of death-driving cysteine proteases called caspases (a complex called the apoptosome) or by preventing the release of mitochondrial apoptogenic factors such as cytochrome c and AIF (apoptosis-inducing factor) into the cytoplasm. After entering the cytoplasm, cytochrome c and AIF directly activate caspases that cleave a set of cellular proteins to cause apoptotic changes. In contrast, pro-apoptotic members of this family, such as Bax and Bak, trigger the release of caspases from death antagonists via heterodimerization and also by inducing the release of mitochondrial apoptogenic factors into the cytoplasm via acting on mitochondrial permeability transition pore, thereby leading to caspase activation. Thus, the Bcl-2 family of proteins acts as a critical life-death decision point within the common pathway of apoptosis.

Limb and Skin Abnormalities in Mice Lacking IKKα

Abstract: The gene encoding inhibitor of kappa B (IκB) kinase α (IKKα; also called IKK1) was disrupted by gene targeting. IKKα-deficient mice died perinatally. In IKKα-deficient fetuses, limb outgrowth was severely impaired despite unaffected skeletal development. The epidermal cells in IKKα-deficient fetuses were highly proliferative with dysregulated epidermal differentiation. In the basal layer, degradation of IκB and nuclear localization of nuclear factor kappa B (NF-κB) were not observed. Thus, IKKα is essential for NF-κB activation in the limb and skin during embryogenesis. In contrast, there was no impairment of NF-κB activation induced by either interleukin-1 or tumor necrosis factor–α in IKKα-deficient embryonic fibroblasts and thymocytes, indicating that IKKα is not essential for cytokine-induced activation of NF-κB.

CKI1, a histidine kinase homolog implicated in cytokinin signal transduction

Abstract: Although cytokinin plays a central role in plant development, little is known about cytokinin signal transduction. Five Arabidopsis thaliana mutants that exhibit typical cytokinin responses, including rapid cell division and shoot formation in tissue culture in the absence of exogenous cytokinin, were isolated by activation transferred DNA tagging. A gene, CKI1, which was tagged in four of the five mutants and induced typical cytokinin responses after introduction and overexpression in plants, was cloned. CKI1 encodes a protein similar to the two-component regulators. These results suggest that CKI1 is involved in cytokinin signal transduction, possibly as a cytokinin receptor.

Genome Structure of the Legume, Lotus japonicus

Abstract: The legume Lotus japonicus has been widely used as a model system to investigate the genetic background of legume-specific phenomena such as symbiotic nitrogen fixation. Here, we report structural features of the L. japonicus genome. The 315.1-Mb sequences determined in this and previous studies correspond to 67% of the genome (472 Mb), and are likely to cover 91.3% of the gene space. Linkage mapping anchored 130-Mb sequences onto the six linkage groups. A total of 10 951 complete and 19 848 partial structures of protein-encoding genes were assigned to the genome. Comparative analysis of these genes revealed the expansion of several functional domains and gene families that are characteristic of L. japonicus. Synteny analysis detected traces of whole-genome duplication and the presence of synteny blocks with other plant genomes to various degrees. This study provides the first opportunity to look into the complex and unique genetic system of legumes.

Sojourner Adjustment: The Case of Foreigners in Japan

Abstract: This article deals with the adjustment of sojourners in Japan. From a psychological perspective, adjustment is closely linked to the development of attitudes in a foreign country. The results of this investigation do not support the idea that foreigners' attitudes toward their host culture automatically improve once they have learned to cope with their new environment in everyday life. This idea has been implied not only by what is widely known as the U-curve theory of adjustment but also by the theory of culture learning. Generally, the results of this investigation suggest a more ambiguous and pessimistic picture of the prospect of overcoming culture shock in a culturally homogeneous environment.