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51.
K Oda Y Misumi Y Ikehara S O Brennan K Hatsuzawa K Nakayama 《Biochemical and biophysical research communications》1992,189(3):1353-1361
We have recently purified and characterized a truncated soluble form of furin from which the predicted transmembrane domain and cytoplasmic tail were deleted (Hatsuzawa, K., Nagahama, M., Takahashi, S., Takada, K., Murakami, K., and Nakayama, K. (1992) J. Biol. Chem. 267, 16094-16099). Our results showed that furin resembles the yeast Kex2 protease with respect to both its enzymic properties and substrate specificity. Here we demonstrate that the soluble form of furin is capable of converting the precursors of albumin and the third component of complement (proalbumin and pro-C3, respectively) in vitro to mature proteins. Thus furin mimics the Ca(2+)-dependent proalbumin and pro-C3 convertases found in the Golgi membranes (Brennan, S. O., and Peach, R. J. (1988) FEBS Lett. 229, 167-170; Oda, K. (1992) J. Biol. Chem. 267, 17465-17471). Furthermore we show that the variant alpha 1-antitrypsin Pittsburgh, which is a specific inhibitor of the Golgi proalbumin convertase, inhibits not only the Golgi pro-C3 convertase, but also the soluble furin. These results suggest a role for furin in the cleavage of proproteins transported via the constitutive pathway. 相似文献
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Y.ODA AND K. TONOMURA. 1996. The presence of any one of the five unlinked MAL loci ( MALI, MAL2, MAL3, MAL4 AND MAL6 ) confers the ability fo ferment maltose on the yeast Saccharomyces cerecvisiae . Each locus is composed of three genes encoding maltose permease, α-glucosididase and MAL activator. Chromosomal DNA of seven representative baking strains has been separated by pulse-field gel electrophoresis and probed with three gense in MAL6 locus. The DNA bands to which all of the three MAL derived probes simultaneously hybridized were chromosome VII carrying MAL1 in all of the strains tested, chromosome XI carrying MAL4 in six strains, chromosome III carrying mal2 in three strains and chromosomes II and VIII carrying MAL3 and MAL6 , respectively, in the one strain. The number of MAL loci in bakig strains was comparable to those of brewing strins. 相似文献
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Group I introns in the liverwort mitochondrial genome: the gene coding for subunit 1 of cytochrome oxidase shares five intron positions with its fungal counterparts. 总被引:3,自引:0,他引:3
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E Ohta K Oda K Yamato Y Nakamura M Takemura N Nozato K Akashi K Ohyama F Michel 《Nucleic acids research》1993,21(5):1297-1305
The complete nucleotide sequence of the mitochondrial DNA (mtDNA) from a liverwort, Marchantia polymorpha, contains thirty-two introns. Twenty-five of these introns possess the characteristic secondary structures and consensus sequences of group II introns. The remaining seven are group I introns, six of which happen to interrupt the gene coding for subunit 1 of cytochrome oxidase (cox1). Interestingly, the insertion sites of one group II and four group I introns in the cox1 gene coincide with those of the respective fungal mitochondrial interns. Moreover, comparison of the four group I introns with their fungal counterparts shows that group I introns inserted at identical genomic sites in different organisms are indeed related to one another, in terms of the peptide sequences generated from the complete or fragmental ORFs encoded by these introns. At the same time, the liverwort introns turned out to be more divergent from their fungal cognates than the latter are from one another. We therefore conclude that vertical transmission from a common ancestor organism is the simplest explanation for the presence of cognate introns in liverwort and fungal mitochondrial genomes. 相似文献
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The objective of this study was to examine the effect of joint angle on the electromyogram (EMG) and mechanomyogram (MMG) during maximal voluntary contraction (MVC). Eight subjects performed maximal isometric plantar flexor torque productions at varying knee and/or ankle angles. Maximal voluntary torque, EMG, and MMG from the soleus (Sol), medial (MG) and lateral gastrocnemius (LG) muscles were measured at different joint angles. At varying knee angles, the root mean squared (rms) MMG amplitude of the MG and LG increased with knee joint extension from 60 degrees to 180 degrees (full extension) in steps of 30 degrees, whereas that of the Sol was constant. At varying ankle angles, the rms-MMG of all muscles (Sol, MG, and LG) decreased with torque as ankle joint extending from 80 degrees (10 degrees dorsiflexion position) to 120 degrees (30 degrees plantar flexion position) in steps of 10 degrees. In each case, changes in the rms-MMG of the three muscles were almost parallel to those in torque. In contrast, there were no significant differences in the rms-EMG of all muscles among all joint angles. Our data suggest that the MMG amplitudes recorded from individual muscles during MVCs can represent relative torque-angle relationships that cannot be represented by the EMG signals. 相似文献
59.
Jan Oscarsson Yoshimitsu Mizunoe Bernt Eric Uhlin David J. Haydon 《Molecular microbiology》1996,20(1):191-199
The Salmonella typhimurium protein SlyAST, originally described as a cytolysin, shows sequence similarities to several known bacterial regulatory proteins. A homologue to the slyASt gene has been localised to min 37 of the Eschericia coli K-12 chromosome and has been designated slyAEC When introduced in trans on a plasmid, the slyAEC gene conferred a haemolytic phenotype on wild-type but not clyA-knockout strains of E. coli K-12. The clyA gene encodes a novel haemolysin that is not expressed by wild-type E. coli under tested laboratory conditions. Western and Northern blot analyses, and DNA-band-shift assays support a model whereby the SlyAEC protein activates clyA expression by binding to the clyA promoter region, thereby supporting the sequence similarity data in suggesting that SlyAST is a haemolysin activator rather than being a haemolysin per se. 相似文献
60.
Kenneth T. Izutsu Sahba Fatherazi Carol M. Belton Dolphine Oda Frank D. Cartwright George E. Kenny 《In vitro cellular & developmental biology. Animal》1996,32(6):361-365
Summary The relations between K+ channel and Cl− channel currents and mycoplasma infection status were studied longitudinally in HSG cells, a human submandibular gland cell
line. The K+ channel currents were disrupted by the occurrence of mycoplasma infection: muscarinic activation of K+ channels and K+ channel expression as estimated by ionomycin- or hypotonically induced K+ current responses were all decreased. Similar decreases in ionomycin- and hypotonically induced responses were observed for
Cl− channels, but only the latter decrease was statistically significant. Also, Cl− currents could be elicited more frequently than K+ currents (63% of cases versus 0%) in infected cells when tested by exposure to hypotonic media, indicating that mycoplasma
infection affects K+ channels relatively more than Cl− channels. These changes occurred in the originally infected cells, were ameliorated when the infection was cleared with sparfloxacin,
and recurred when the cells were reinfected. Such changes would be expected to result in hyposecretion of salivary fluid if
they occurredin vivo. 相似文献