Shouhei Kobayashi

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To study the role of the centrosome in microtubule organization in interphase cells, we developed a method for obtaining cytoplasts (cells lacking a nucleus) that did or did not contain centrosomes. After drug-induced microtubule depolymerization, cytoplasts with centrosomes made from sparsely plated cells reconstituted a microtubule array typical of normal(More)
Although ubiquitin is thought to be important for the autophagic sequestration of invading bacteria (also called xenophagy), its precise role remains largely enigmatic. Here we determined how ubiquitin is involved in this process. After invasion, ubiquitin is conjugated to host cellular proteins in endosomes that contain Salmonella or transfection(More)
Endocytosis has been implicated in the cellular uptake of arginine-rich, cell-penetrating peptides (CPPs). However, accumulating evidence suggests that certain conditions allow the direct, non-endocytic penetration of arginine-rich peptides through the plasma membrane. We previously showed that Alexa Fluor 488-labeled dodeca-arginine (R12-Alexa488) directly(More)
We describe a human autoantiserum that recognizes specific determinants present both on the nuclear envelope of interphase cells and the periphery of metaphase chromosomes. These determinants are highly conserved through evolution and present on a protein with an apparent molecular weight of 33,000. This 33 kd protein, which we call "perichromin," appears(More)
The human cell cycle was synchronized and the chromosomes were isolated by a centrifugation method using two representative solutions for chromosome isolation (a polyamine buffer, PAB and citric acid solution, CAS) and fixatives. The centrifugation method yielded sufficient amounts of human metaphase chromosomes. Observation of the isolated chromosomes by(More)
A comparative proteome analysis of human metaphase chromosomes between a typical epithelial-like cell, HeLa S3, and a lymphoma-type cell, BALL-1, was performed. One-dimensional (1-D) SDS-PAGE and radical-free and highly reducing two-dimensional electrophoresis (RFHR 2-DE) detected more than 200 proteins from chromosomes isolated from HeLa S3 cells, among(More)
In molecular communication, a group of biological nanomachines communicates through exchanging molecules and collectively performs application dependent tasks. An open research issue in molecular communication is to establish interfaces to interconnect the molecular communication environment (e.g., inside the human body) and its external environment (e.g.,(More)
In higher eukaryotic cells, DNA molecules are present as chromatin fibers, complexes of DNA with various types of proteins; chromatin fibers are highly condensed in metaphase chromosomes during mitosis. Although the formation of the metaphase chromosome structure is essential for the equal segregation of replicated chromosomal DNA into the daughter cells,(More)