Abstract：
:We investigated the relative contributions of phagocytosis and plasma membrane transport to the uptake of amino acids and a protein (egg albumin) in amounts which allow Tetrahymena thermophila to grow and multiply. We used a mutant capable of indefinite growth without food vacuole formation (phagocytosis) and its wild type (phagocytosis-competent) isogenic parental strain. Our results suggest that phagocytosis is not required for free amino acid uptake, most or all of which can be attributed to carrier-mediated transport systems, apparently located on the plasma membrane. In contrast, phagocytosis is required for utilization of the protein. Proteins can supply required amino acids in amounts sufficient for growth only when food vacuoles are formed. We conclude that Tetrahymena thermophila either possesses no endocytic mechanisms at the cell surface other than food vacuole formation or, if it does, these putative mechanisms are not capable of nutritionally meaningful rates of protein uptake.
journal_name
J Cell Scijournal_title
Journal of cell scienceauthors
Orias E,Rasmussen Lkeywords:
subject
Has Abstractpub_date
1979-04-01 00:00:00pages
343-53eissn
0021-9533issn
1477-9137journal_volume
36pub_type
杂志文章abstract：:Our understanding of cells has progressed rapidly in recent years, mainly because of technological advances. Modern technology now allows us to observe molecular processes in living cells with high spatial and temporal resolution. At the same time, we are beginning to compile the molecular parts list of cells. However...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.200295
更新日期：2017-09-01 00:00:00
abstract：:Cell-free extracts of Xenopus eggs support nuclear assembly and DNA replication in vitro. Extracts supplemented with the protein phosphatase inhibitor microcystin-LR displayed various inhibitory effects at different concentrations of the toxin. In the presence of cycloheximide, additions of microcystin did not induce ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1995-01-01 00:00:00
abstract：:Guinea pig sperm were suspended in calcium-containing medium supplemented with various concentrations of the tetrasaccharide, stachyose. At concentrations up to and including 0.6 M, stachyose was without effect on the A23187-induced acrosome reaction. At 1.0 M stachyose, greater than 97% of sperm retained their acroso...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1991-12-01 00:00:00
abstract：:An analysis of the concanavalinA binding polypeptide components of bovine tongue epithelial desmosomes reveals that in addition to the known desmosomal glycoproteins of 100/115K (the 'desmocollins'), 140K and 160/165K ('desmoglein 1') there is an uncharacterized glycoprotein of 125K (K = Mr x 10(-3). This latter polyp...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1988-02-01 00:00:00
abstract：:Connexin 30 (Cx30), a member of the large gap-junction protein family, plays a role in the homeostasis of the epidermis and inner ear through gap junctional intercellular communication (GJIC). Here, we investigate the underlying mechanisms of four autosomal dominant Cx30 gene mutations that are linked to hearing loss ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.138230
更新日期：2014-04-15 00:00:00
abstract：:Super-resolution fluorescence imaging by single-molecule photoactivation or photoswitching and position determination (localization microscopy) has the potential to fundamentally revolutionize our understanding of how cellular function is encoded at the molecular level. Among all powerful, high-resolution imaging tech...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.123612
更新日期：2013-08-15 00:00:00
abstract：:Protein kinases AKT and PKBR1 of Dictyostelium belong to the AGC protein kinase superfamily. AKT and PKBR1 are phosphorylated at similar sites by phosphoinositide-dependent kinase 1 (PDK1) and TORC2 kinases; however, they have different subcellular localizing domains. AKT has a phosphoinositide 3-kinase (PI3K)/phospha...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.064022
更新日期：2010-03-15 00:00:00
abstract：:The microtubule-associated protein tau interacts with the SH3 domain of non-receptor Src family protein tyrosine kinases. A potential consequence of the SH3 interaction is the upregulation of tyrosine kinase activity. Here we investigated the activation of Src or Fyn by tau, both in vitro and in vivo. Tau increased th...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.03378
更新日期：2007-03-01 00:00:00
abstract：:The intracellular protozoan parasite Toxoplasma gondii, like all members of the phylum Apicomplexa, is known to possess many organelles: in addition to mitochondria and the compartments of the secretory pathway, there is a reduced chloroplast (the apicoplast) and the phylum-specific components of the apical complex: d...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2000-07-01 00:00:00
abstract：:The plasma membrane of cells is composed of lateral heterogeneities, patches and microdomains. These membrane microdomains or lipid rafts are enriched in glycosphingolipids and cholesterol and have been implicated in cellular processes such as membrane sorting and signal transduction. In this study we investigated the...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2002-06-15 00:00:00
abstract：:Fibrin deposits in tumor beds are an intriguing phenomenon. It has been suggested that fibrin plays a role as a provisional matrix in which the tumor grows and induces development of a vascular network. On the other hand fibrin possibly protects the tumor nodule from host defense mechanisms. We therefore investigate w...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1993-10-01 00:00:00
abstract：:The telomeric repeat binding factor 2 (TRF2) specifically recognizes TTAGGG tandem repeats at chromosomal ends. Unexpectedly immunofluorescence studies revealed a prominent nucleolar localization of TRF2 in human cells, which appeared as discrete dots with sizes similar to those present in the nucleoplasm. The TRF2 do...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01249
更新日期：2004-08-01 00:00:00
abstract：:The protozoan parasite Giardia intestinalis (also known as Giardia lamblia) is a major waterborne pathogen. During its life cycle, Giardia alternates between the actively growing trophozoite, which has two diploid nuclei with low levels of allelic heterozygosity, and the infectious cyst, which has four nuclei and a to...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.103879
更新日期：2012-05-15 00:00:00
abstract：:Motile eukaryotic flagella beat through coordinated activity of dynein motor proteins; however, the mechanisms of dynein coordination and regulation are incompletely understood. The inner dynein arm (IDA) f complex (also known as the I1 complex), and the tether and tether head (T/TH) complex are thought to be key regu...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.239855
更新日期：2020-01-23 00:00:00
abstract：:KLP61F in Drosophila and other BimC kinesins are essential for spindle bipolarity across species; loss of BimC function generates high frequencies of monopolar spindles. Concomitant loss of Kar3 kinesin function increases the frequency of bipolar spindles although the underlying mechanism is not known. Recent studies ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01334
更新日期：2004-10-01 00:00:00
abstract：:Present in organisms ranging from yeast to man, homologues of the Saccharomyces cerevisiae ubiquitin-conjugating enzyme CDC34 have been shown to play important roles in the regulation of cell cycle progression and checkpoint function. Here we analyze the expression and intracellular localization of endogenous CDC34 du...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2000-05-01 00:00:00
abstract：:Rab GTPases are key regulators of intracellular trafficking, and cycle between a GTP-bound active state and a GDP-bound inactive state. This cycle is regulated by guanine-nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Several efforts have been made in connecting the correct GEFs and GAPs to ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.216630
更新日期：2018-09-03 00:00:00
abstract：:MACF (microtubule actin cross-linking factor) is a large, 608-kDa protein that can associate with both actin microfilaments and microtubules (MTs). Structurally, MACF can be divided into 3 domains: an N-terminal domain that contains both a calponin type actin-binding domain and a plakin domain; a rod domain that is co...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2001-01-01 00:00:00
abstract：:In human red blood cells, protein 4.1 (4.1R) stabilizes the spectrin-actin network and anchors it to the plasma membrane. To contribute to the characterization of functional roles of 4.1R in nonerythroid cells, we analysed the effect of ectopic expression of 4.1R isoforms on interphase microtubules in fibroblastic cel...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.01544
更新日期：2004-12-01 00:00:00
abstract：:Clusterin expression is increased in tissues undergoing apoptosis, including neurodegenerative retina, but the causal relationships remain to be clarified. To test the hypothesis that overexpression of clusterin could induce apoptosis in neurons, transgenic mice were generated in which rat clusterin transgene was expr...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1999-05-01 00:00:00
abstract：:Failure to form proper synapses in mechanosensory hair cells, the sensory cells responsible for hearing and balance, leads to deafness and balance disorders. Ribbons are electron-dense structures that tether synaptic vesicles to the presynaptic zone of mechanosensory hair cells where they are juxtaposed with the post-...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.182592
更新日期：2016-06-01 00:00:00
abstract：:Neurofilaments (NFs) are the major intermediate filaments (IFs) of mature neurons. They play important roles in the structure and function of axons. Recently, two mutations in the neurofilament light (NFL) subunit have been identified in families affected by Charcot-Marie-Tooth (CMT) neuropathy type 2. We have charact...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.00148
更新日期：2002-12-15 00:00:00
abstract：:Start is the main decision point in the eukaryotic cell cycle at which cells commit to a new round of cell division. It involves the irreversible activation of a transcriptional programme through the inactivation of Start transcriptional repressors: the retinoblastoma family in mammals, or Whi5 and its recently identi...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.251413
更新日期：2020-12-21 00:00:00
abstract：:Epidermal growth factor receptor has been localized to the proliferative cell layers in a variety of stratified squamous epithelia. In the current study, the rat cornea was used as an experimental model to determine if epidermal growth factor receptor is concentrated in epithelial stem cells. Epidermal growth factor r...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1993-09-01 00:00:00
abstract：:The cornified cell envelope (CE), a structure formed in the outermost layers of stratified squamous epithelia, provides a physical barrier against environmental insults. It is composed of several structural proteins, which are irreversibly crosslinked by calcium-activated transglutaminases. The small proline rich prot...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：2001-11-01 00:00:00
abstract：:Previously, we have identified a class of retinal degeneration mutants in Drosophila in which the normally transient interaction between arrestin2 (Arr2) and rhodopsin is stabilized and the complexes are rapidly internalized into the cell body by receptor-mediated endocytosis. The accumulation of protein complexes in ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.03052
更新日期：2006-08-01 00:00:00
abstract：:Of the classical compartments of eukaryotic cells, peroxisomes were the last to be discovered. They are small, single-membrane-bound vesicles involved in cellular metabolism, most notably the beta-oxidation of fatty acids. Characterization of their properties and behavior has progressed rather slowly. However, during ...
journal_title：Journal of cell science
pub_type： 杂志文章,评审
doi：10.1242/jcs.02893
更新日期：2006-03-15 00:00:00
abstract：:Mutations in a gene (Klp38B) encoding a novel kinesin-like protein in Drosophila melanogaster lead to the formation of polyploid cells in the larval central nervous system and in the follicle cells of adult egg chambers. Some homozygous mutants survive to adulthood and also exhibit morphological defects indicative of ...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1997-04-01 00:00:00
abstract：:The atomic force microscope (AFM) was used to directly image hippocampal neurons and glia. Using chemically fixed and living cells it was possible to reconstruct three-dimensional cell structure and detect sub-cellular features such as the nucleus, mitochondria and filaments. By repeatedly scanning a single living cel...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：
更新日期：1993-02-01 00:00:00
abstract：:In the developing Drosophila eye, the centrioles of the differentiating retinal cells are not surrounded by the microtubule-nucleating γ-tubulin, suggesting that they are unable to organize functional microtubule-organizing centers. Consistent with this idea, Cnn and Spd-2, which are involved in γ-tubulin recruitment,...
journal_title：Journal of cell science
pub_type： 杂志文章
doi：10.1242/jcs.211441
更新日期：2018-02-22 00:00:00
