排序方式: 共有38条查询结果,搜索用时 15 毫秒
31.
Receptor-mediated transport and deposition of complement component C3 into developing chicken oocytes 总被引:1,自引:0,他引:1
Recheis B Rumpler H Schneider WJ Nimpf J 《Cellular and molecular life sciences : CMLS》2005,62(16):1871-1880
Immunological resistance of the chick embryo is dependent upon IgG present in the yolk of the layed egg. Here we show that complement factor 3 (C3), a key component of the humoral complement system, is a yolk component of chicken eggs. C3 is transported into oocytes by LR8-mediated endocytosis. LR8 also binds and transports other major yolk components such as vitellogenin, very-low-density lipoprotein, and α2-macroglobulin. Expression studies of LR8 during chicken development and oocyte maturation, in combination with studies on the uptake of individual yolk components, suggest the following model for oocyte maturation in the chicken: all oocytes present in the ovary contain high levels of LR8 mRNA and protein long before the onset of oocyte maturation. Selected oocytes gain access to yolk precursors, and LR8 binds, internalizes, and deposits the major yolk components in the ratio of their relative abundance in the accessible pool.Received 9 May 2005; received after revision 6 June 2005; accepted 13 June 2005 相似文献
32.
Evidence for actin-dependent organelle movement was first obtained from studies of cytoplasmic streaming in plants. These studies, together with cell-free organelle motility studies and biophysical analyses of muscle myosin, support a model whereby organelle-associated motor molecules utilize the energy of adenosine triphosphate binding and hydrolysis to drive movement along F-actin tracks Recent studies indicate that this mechanism for organelle movement may be responsible for organelle and vesicle movement during secretion, endocytosis and mitochondrial inheritance in a variety of eukaryotes. 相似文献
33.
Shengsong Tang Hanzhi Liu Guibin Chen Qing Rao Yiqi Geng Guoguang Zheng Dexian Zheng Kefu Wu 《科学通报(英文版)》2000,45(18):1697-1703
The binding of recombinant human macrophage colony-stimulating factor (M-CSF) soluble receptor (rh-M-CSF-sR) to membrane-bound
macrophage colony stimulating factor (m-M-CSF) and the internalization and recycling of rh-M-CSF-sR/m-M-CSF complexes mediated
by m-M-CSF were studied with a model of J6-1 cell line. The results indicated that m-M-CSF bound rh-M-CSF-sR with high affinity
(kd = 1.78×1012 mol/L) and mediated a temperature- and energydependent internalization of rh-M-CSF-sR, and that internalized rh-M-CSF-sR
could return to the cell surface in an m-M-CSF-bound state, suggesting that m-M-CSF may have a capability to mediate the internalization
and recycling of rh-M-CSF-sR/m-M-CSF complexes. In addition, the half-lives of cell-associated M-CSF and its receptor of stimulated
normal human cord blood mononuclear cells (CBMCs) and 4 leukemic cell lines were measured by indirect immunofluorescence and
flow cytometry. The results showed that the half-lives of the various kinds of M-CSF isoforms and M-CSF-R in 4 leukemic cells,
except those of membrane-bound M-CSF receptor (M-CSF-mR) of K562 and HL-60 cells, were longer than those of corresponding
M-CSF isoform and its receptor in stimulated normal human CBMCs, suggesting that there is a slow degradation rate of cell-associated
M-CSF and its receptor in leukemic cells. 相似文献
34.
Shapiro JL Wen X Okamoto CT Wang HJ Lyngstadaas SP Goldberg M Snead ML Paine ML 《Cellular and molecular life sciences : CMLS》2007,64(2):244-256
Proteins of the developing enamel matrix include amelogenin, ameloblastin and enamelin. Of these three proteins amelogenin
predominates. Protein-protein interactions are likely to occur at the ameloblast Tomes’ processes between membrane-bound proteins
and secreted enamel matrix proteins. Such protein-protein interactions could be associated with cell signaling or endocytosis.
CD63 and Lamp1 are ubiquitously expressed, are lysosomal integral membrane proteins, and localize to the plasma membrane.
CD63 and Lamp1 interact with amelogenin in vitro. In this study our objective was to study the molecular events of intercellular trafficking of an exogenous source of amelogenin,
and related this movement to the spatiotemporal expression of CD63 and Lamp1 using various cell lineages. Exogenously added
amelogenin moves rapidly into the cell into established Lamp1-positive vesicles that subsequently localize to the perinuclear
region. These data indicate a possible mechanism by which amelogenin, or degraded amelogenin peptides, are removed from the
extracellular matrix during enamel formation and maturation.
Received 27 September 2006; received after revision 24 November 2006; accepted 5 December 2006 相似文献
35.
植物病原丝状真菌内吞过程与菌丝细胞的生长、分化以及发育等关系密切。禾谷炭疽菌是一种半活体营养型植物病原丝状真菌,可以侵染玉米、小麦、高粱等禾本科植物而引起炭疽病,前人对其分泌蛋白在致病性过程中作用的研究较多,但对致病性过程中内吞相关蛋白的研究尚未见报道。构巢曲霉中具有DPFxD基序的蛋白发挥着受体介导的内吞信号作用,有助于实现真菌的内吞过程。基于构巢曲霉DPFxD蛋白序列,通过Blastp比对分析和关键词搜索,明确禾谷炭疽菌中存在48个DPFxD蛋白序列,并利用生物信息学分析工具对上述蛋白进行了亚细胞定位、信号肽、二级结构等特征解析,以及对DPFxD蛋白和同源蛋白开展遗传关系分析,明确其与炭疽菌属中C. incanum、C.sublineola、C. tofieldiae具有较高的同源性。研究成果为进一步探究DPFxD蛋白功能奠定理论基础,也为其他炭疽菌内吞作用蛋白研究提供重要的理论指导。 相似文献
36.
The cellular functions of clathrin 总被引:3,自引:0,他引:3
Royle SJ 《Cellular and molecular life sciences : CMLS》2006,63(16):1823-1832
Membranes and proteins are moved around the cell in small vesicles. A protein coat aids the budding of such vesicles from
donor membranes. The major type of coat used by the cell is composed of clathrin, a three-legged protein that can form lattice-like
coats on membranes destined for trafficking. In this review, I outline what we know about clathrin and discuss some recent
advances in understanding the basic biology of this fascinating molecule, which include building a molecular model of a clathrin
lattice and discovery of a new function for clathrin that occurs during mitosis.
Received 12 December 2005; received after revision 21 March 2006; accepted 29 March 2006 相似文献
37.
J. Cuadras 《Cellular and molecular life sciences : CMLS》1985,41(12):1590-1591
Summary Small extrusions of glial cytoplasm are endocytosed by neuron cell bodies of the crayfishProcambarus. Vesicles are double walled with the external membrane issuing from the neuron and the internal one from the glia. This could be a system for the transfer of glial cytoplasmic free proteins to neurons. 相似文献
38.
Modification of ligand-gated receptor function at the postsynaptic domain is one of the most important mechanisms by which
the efficacy of synaptic transmission in the nervous system is regulated. Traditionally, these types of modifications have
been thought to be achieved mainly by altering the channel-gating properties or conductance of the receptors. However, recent
evidence suggests that AMPA (α-amino-3-hydroxyl-5-methyl-4-isoxayolepropionic acid)-type ligand-gated glutamate receptors are continuously recycling between
the plasma membrane and the intracellular compartments via vesicle-mediated plasma membrane insertion and clathrin-dependent
endocytosis. Regulation of either receptor insertion or endocytosis results in a rapid change in the number of these receptors
expressed on the plasma membrane surface and in the receptor-mediated responses, thereby playing an important role in mediating
certain forms of synaptic plasticity. Thus, controlling the number of postsynaptic receptors by regulating the intracellular
trafficking and plasma membrane expression of the postsynaptic receptors may be a common and important mechanism of synaptic
plasticity in the mammalian central nervous system. 相似文献