Abstract:
:The Acanthamoeba myosin-IA and myosin-IB molecular motors bind to membranes, so they may produce the force to move organelles and membranes along actin filaments. We have determined the rate constants for the actin-activated myosin-I ATPase by pre-steady state kinetic analysis. ATP binds rapidly to myosin-I and dissociates the enzyme from actin filaments at a rate > 500 s-1. Myosin-I hydrolyzes ATP to ADP and inorganic phosphate (Pi) at 20-50 s-1. Phosphate dissociation is the rate limiting step in the ATPase cycle, 0.01 s-1 for myosin-I alone and at 10 s-1 when myosin-I is bound to actin filaments. ADP dissociation is rapid. Phosphorylation controls the ATPase cycle by increasing the rate of phosphate release from myosin-I bound to actin. At steady state the major species are myosin-ATP and myosin-ADP-Pi, which rapidly bind to and dissociate from actin filaments. During the ATPase cycle myosin-I binds so weakly to actin filaments that it cannot support processive movement like kinesin, unless several motors cluster together on a membrane or actin filament. These properties of the enzyme emphasize the importance of characterizing mechanisms that promote the self-association of myosin-I isoforms at specific binding sites in cells.
journal_name
Cell Struct Functjournal_title
Cell structure and functionauthors
Pollard TD,Ostap EMdoi
10.1247/csf.21.351subject
Has Abstractpub_date
1996-10-01 00:00:00pages
351-6issue
5eissn
0386-7196issn
1347-3700journal_volume
21pub_type
杂志文章,评审abstract::Recent studies have revealed various biological functions for repetitive sequences, which make up about half of the human genome. One such sequence, major satellites, which are tandem repetitive sequences adjacent to the centromere, have been shown to be a kinetochore component that plays a role in the formation and f...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.12009
更新日期:2012-01-01 00:00:00
abstract::The change in distribution of centrosomal phosphoproteins was examined in sea urchin eggs from fertilization to the first cleavage by immunofluorescence staining with the anti-phosphoprotein antibodies, MPM-1 and MPM-2. The antibodies reacted with female pronuclei in unfertilized eggs as well as centriolar complexes l...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.15.13
更新日期:1990-02-01 00:00:00
abstract::We constructed a fusion protein of the cell-binding domain of human fibronectin and human basic fibroblast growth factor, and prepared a polypeptide with both cell-adhesive activity and growth factor activity. A human gene fragment coding for basic fibroblast growth factor was amplified by the polymerase chain reactio...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.19.37
更新日期:1994-02-01 00:00:00
abstract::Here, we would like to point out important milestones in the study of nuclear radial positioning and gene expression during differentiation processes. In addition, changes in the histone signature that significantly precede various differentiation pathways are reviewed. We address the regulatory functions of chromatin...
journal_title:Cell structure and function
pub_type: 杂志文章,评审
doi:10.1247/csf.09021
更新日期:2010-01-01 00:00:00
abstract::The fine structural localization of albumin in rat liver parenchymal cells was determined by an improved immunocytochemical method and serial sectioning. Albumin in the secretory apparatus of the parenchymal cells was present in segments of the rough endoplasmic reticulum, interrupted with negative segments, in transp...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.12.251
更新日期:1987-06-01 00:00:00
abstract::A monoclonal type M-immunoglobulin (IgM) was generated in mice against a nuclease-urea extract of HeLa metaphase chromosomes. This antibody stains metaphase chromosomes from a variety of mammalian cultured cell types by indirect immunofluorescence. Antibody 12C7 reacts by western transfer technique with histone H1 in ...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.16.323
更新日期:1991-08-01 00:00:00
abstract::Ran is a nuclear Ras-like GTPase that is required for various nuclear events including the bi-directional transport of proteins and ribonucleoproteins through the nuclear pore complex, spindle formation, and reassembly of the nuclear envelope. One of the key regulators of Ran is RanGAP1, a Ran specific GTPase activati...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.30.69
更新日期:2005-01-01 00:00:00
abstract::The distribution of Ca2+ in dividing cells of the maize root tip was examined by potassium pyroantimonate precipitation and EGTA treatment methods. Ca2+ was found in most of the cell organelles, such as the matrix of the mitochondria, the thylakoid membrane of the proplastid and the Golgi vesicles, and on the plasma m...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.18.389
更新日期:1993-12-01 00:00:00
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journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.27.479
更新日期:2002-12-01 00:00:00
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journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.14.87
更新日期:1989-02-01 00:00:00
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journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.14.659
更新日期:1989-12-01 00:00:00
abstract::Multiple type I and II hair keratins are expressed in hair-forming cells but the role of each protein in hair fiber formation remains obscure. In this study, recombinant proteins of human type I hair keratins (K35, K36 and K38) and type II hair keratins (K81 and K85) were prepared using bacterial expression systems. T...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.13021
更新日期:2014-01-01 00:00:00
abstract::Upon tryptic digestion of synaptosomes, ATPase activities decreased in the order of Cl(-)-ATPase greater than or equal to Na+,K+-ATPase greater than anion-insensitive Mg2+-ATPase. Upon synaptosome treatment with hypotonic solution, Cl(-)-ATPase or anion-insensitive Mg2+-ATPase was slightly inactivated, while Na+,K+-AT...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.13.105
更新日期:1988-04-01 00:00:00
abstract::The efficacy of anticancer agents significantly depends on the differential susceptibility of undifferentiated cancer cells and differentiated normal cells to undergo apoptosis. We previously found that enhanced expression of RPS3a/nbl, which apparently encodes a ribosomal protein, seems to prime cells for apoptosis, ...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.25.103
更新日期:2000-04-01 00:00:00
abstract::Primary hepatocytes were cultured on collagen gel in serum-free, alpha-modified Eagle's minimum essential medium containing 0.1 microM insulin, 0.1 microM dexamethasone, 10 mM pyruvate and supplements such as glucagon, epinephrine or growth hormone. The activities of alkaline phosphatase, 5'-nucleotidase and gamma-glu...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.18.73
更新日期:1993-02-01 00:00:00
abstract::The morphology and intramembranous particle (IMP) distribution of spermatozoa were investigated in four species of cyprinid fishes, Gnathopogon elongatus elongatus, Pseudogobio esocinus, Acheilognathus lanceolatus and Puntius tetrazona. In particular, observation of IMP distribution was conducted as an aspect of compa...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.20.293
更新日期:1995-08-01 00:00:00
abstract::To evaluate the role of VAMP8/endobrevin in constitutive exocytosis, we have examined the exocytotic pathways of VAMP8 and human growth hormone, both GFP-tagged, by total internal reflection fluorescence microscopy (TIRF-M). Human GH-GFP and VAMP8-GFP were similarly expressed in small round vesicles and elongated tubu...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.09013
更新日期:2009-01-01 00:00:00
abstract::Vascular endothelial cells possess antithrombotic properties, which are determined by the balance between plasminogen activators (PAs) and PA inhibitors (PAls). A cell line, TKM-33, has been established and cloned from human umbilical vein endothelial cells, was previously reported to produce a large amount of urokina...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.24.71
更新日期:1999-04-01 00:00:00
abstract::Phosphorylation of regulatory light chain (RMLC) of myosin II at Ser19/Thr18 is likely to play important roles in controlling the morphological changes seen during cell division of cultured mammalian cells. Phosphorylation of RMLC regulates the activity of myosin II, an essntial motor for cytokinesis, and phosphorylat...
journal_title:Cell structure and function
pub_type: 杂志文章,评审
doi:10.1247/csf.26.639
更新日期:2001-12-01 00:00:00
abstract::Staurosporine has been reported to cause arrest of cells in G1 phase at low concentration and in G2 phase at high concentration. This raises the question of why the effects of staurosporine on the cell cycle depend on the applied concentration. In order to verify these multiple functions of staurosporine in Meth-A cel...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.24.457
更新日期:1999-12-01 00:00:00
abstract::Two types of DNA ligase, I and II, have been purified approximately 4,000-fold from mouse testes and 500-fold from nuclei of mouse spermatocytes. DNA ligase I and II consisted of single polypeptides with molecular weights of 95,000 and 65,000, respectively, according to the estimation by SDS-polyacrylamide gel electro...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.15.67
更新日期:1990-02-01 00:00:00
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journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.14.173
更新日期:1989-04-01 00:00:00
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journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.19.279
更新日期:1994-10-01 00:00:00
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journal_title:Cell structure and function
pub_type: 杂志文章,评审
doi:10.1247/csf.22.219
更新日期:1997-02-01 00:00:00
abstract::1. Cofilin is an essential actin-regulating protein widely distributed in all eucaryotes. The structure and function of cofilin are conserved during evolution. 2. Cofilin depolymerizes F-actin in vitro at alkaline pH and severs F-actin in vitro at pH lower than 7.3. Overexpression of cofilin in viable cells induced bu...
journal_title:Cell structure and function
pub_type: 杂志文章,评审
doi:10.1247/csf.21.421
更新日期:1996-10-01 00:00:00
abstract::Cultured hepatic stellate cells (HSCs) are known to change their morphology and function with respect to the production of extracellular matrices (ECMs) and matrix metalloproteinases (MMPs) in response to ECM components. We examined the regulatory role of the native form of type I collagen fibrils in pro-MMP-2 product...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.28.505
更新日期:2003-12-01 00:00:00
abstract::A method has been developed to isolate pure preparations of nuclei in high yield from commercially available viable rice embryos (germ), employing extraction with buffer solution containing glycerol (without detergent) and polyamine, followed by centrifugation on a 30% Percoll cushion. The intactness of the isolated n...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.17.87
更新日期:1992-04-01 00:00:00
abstract::The in vivo structure of the smooth endoplasmic reticulum (ER) was visualized in rat and mouse cerebellar Purkinje cells by using quick-freezing techniques followed by freeze-substitution for ultrathin-sectioning or freeze-fracturing and deep-etching for replicas. High magnification electron microscopy of the ultrathi...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.23.373
更新日期:1998-12-01 00:00:00
abstract::DNA synthesis of WF-1 fibroblasts derived from a patient with Werner's syndrome was stimulated by fetal calf serum and adult human serum but not by various mitogens including epidermal growth factor, platelet-derived growth factor (PDGF), fibroblast growth factor, insulin and 12-O-tetradecanoylphorbol-13-acetate (TPA)...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.13.471
更新日期:1988-12-01 00:00:00
abstract::The amount of intact 40S rRNA precursor was followed by Northern hybridization in the course of the early embryogenesis of wild-type Xenopus laevis and its anucleolate mutant. The total amount of 40S rRNA precursor did not alter appreciably until the midblastula stage, decreased at the late blastula stage, and then in...
journal_title:Cell structure and function
pub_type: 杂志文章
doi:10.1247/csf.13.113
更新日期:1988-04-01 00:00:00