Abstract:
:Tropomyosin is a key component of the contractile systems found in muscle and nonmuscle cells of higher eukaryotes. Based on properties common to all tropomyosins, we have purified a protein from Saccharomyces cerevisiae that resembles tropomyosins from higher cells. The yeast protein remains soluble after heat treatment at 90 degrees C, has an apparent polypeptide molecular weight of 33,000, an isoelectric point of 4.5, a Stokes radius of 3.5 nm, and a sedimentation coefficient of 2.6 S. It binds F-actin in a Mg2+-dependent, KCl-modulated manner, up to a stoichiometry of about 1 polypeptide per 3.0 actin monomers. In all these properties it is very similar to tropomyosins from higher cells. Antigen-affinity-purified antibodies specifically recognize the Mr 33,000 polypeptide among total yeast proteins and crossreact with bovine brain tropomyosin. In addition, the antibodies specifically crossreact with heat-stable Mr 33,000 polypeptides in extracts of Schizosaccharomyces pombe and Physarum polycephalum. Our detection of tropomyosin in lower eukaryotes suggests that they might have contractile systems very similar to those found in higher organisms.
journal_name
Proc Natl Acad Sci U S Aauthors
Liu HP,Bretscher Adoi
10.1073/pnas.86.1.90subject
Has Abstractpub_date
1989-01-01 00:00:00pages
90-3issue
1eissn
0027-8424issn
1091-6490journal_volume
86pub_type
杂志文章abstract::We have analyzed the spectra of UV-induced mutations in the lacI gene of a wild-type and an mfd strain of Escherichia coli. mfd strains have been recently proposed to be deficient in a factor coupling DNA repair and transcription. Analysis of UV-induced mutations occurring at adjacent pyrimidines showed that mutations...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 临床试验,杂志文章
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更新日期:1983-03-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1974-01-01 00:00:00
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更新日期:1986-01-01 00:00:00
abstract::In the plant Nicotiana plumbaginifolia, manganese superoxide dismutase (MnSOD) is synthesized in the cytoplasm as a preprotein and is subsequently translocated to the mitochondrial matrix with corresponding cleavage of an NH2-terminal leader sequence. To determine whether the plant enzyme could replace the endogenous ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1989-05-01 00:00:00
abstract::Spiperone, a dopamine antagonist widely used as a specific ligand for dopamine and serotonin receptors, is actively accumulated into the F4C1 strain of rat pituitary tumor cells. The accumulation of 10 nM [3H]spiperone was linear for 3 min and reached a steady state after 10 min. Spiperone accumulation was reduced 50%...
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