Kazuhiro Shiba

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Familial adenomatous polyposis coli (FAP) is a disease characterized by the development of multiple colorectal adenomas, and affected individuals carry germline mutations in the APC gene. With the use of a conditional gene targeting system, a mouse model of FAP was created that circumvents the embryonic lethality of Apc deficiency and directs Apc(More)
The suhB gene is located at 55 min on the Escherichia coli chromosome and encodes a protein of 268 amino acids. Mutant alleles of suhB have been isolated as extragenic suppressors for the protein secretion mutation (secY24), the heat shock response mutation (rpoH15), and the DNA synthesis mutation (dnaB121) (K. Shiba, K. Ito, and T. Yura, J. Bacteriol.(More)
We describe the properties of a temperature-sensitive mutant, ts24, of Escherichia coli. The mutant has a conditional defect in export of periplasmic and outer membrane proteins. At 42 degrees C, precursor forms of these proteins accumulate within the cell where they are protected from digestion by externally added trypsin. The accumulated precursors are(More)
We studied the patterns of membrane potential changes in laryngeal motoneurons (LMs) during vocalization, coughing, swallowing, sneezing, and the aspiration reflex in decerebrate paralyzed cats. LMs, identified by antidromic activation from the recurrent laryngeal nerve, were expiratory (ELMs) or inspiratory (ILMs) cells that depolarized during their(More)
The rpoH15 mutant cannot grow at or above 34 degrees C, because it produces an altered sigma 32 protein that is largely deficient in the transcription of the heat shock genes. Extragenic suppressor mutations (suhB) located at 55 min on the Escherichia coli chromosome endowed the mutant cell with the ability to grow at 40 degrees C and the inability to grow(More)
The universal genetic code is determined by the aminoacylation of tRNAs. In spite of the universality of the code, there are barriers to aminoacylation across taxonomic domains. These barriers are thought to correlate with the co-segregation of sequences of synthetases and tRNAs into distinct taxonomic domains. By contrast, we show here examples of(More)
We describe a novel method for constructing pools of DNA sequences that encode large proteins with molecular diversity. Sets of primer pairs that form 8 to 10 complementary base pairs in the 3' region and have double mismatch pairs at their 3'-OH ends were designed so that primer dimers recreated short stretches of DNA (microgenes) devoid of termination(More)
The nucleotide 73 (N73) "discriminator" base in the acceptor stem is a key element for efficient and specific aminoacylation of tRNAs and of microhelix substrates derived from tRNA acceptor stems. This nucleotide was possibly one of the first to be used for differentiating among groups of early RNA substrates by tRNA synthetases. In contrast to many other(More)
BACKGROUND The epithelial reticular basement membrane (Rbm) of the airway wall thickens in patients with asthma. However, whether the thickening parallels whole airway wall thickening, which limits airflow, is unknown. The aim of this study was to examine the correlation between the bronchial Rbm thickening and whole airway wall thickening in asthma. In(More)
A cold-sensitive mutant was isolated among temperature-resistant revertants of the secY24 mutant defective in secretion of envelope proteins across the cytoplasmic membrane at 42 degrees C. A single mutation, designated ssyA3, is responsible both for the extragenic suppression of secY and for the cold-sensitive growth. In contrast to the parental secY24(More)