Cell polarity

Several nonconventional cadherins that contain cadherin repeats have been described but they have specific features not found in the classical cadherins [1]. The cadherin Flamingo, originally detected in Drosophila, contains seven transmembrane segments and in this respect resembles G protein-coupled receptors. The extracellular domain of Flamingo and its mammalian homologs is composed of cadherin repeats as well as EGF-like and laminin motifs. The seven transmembrane span cadherins have a role in homotypic cell interactions and in the establishment of cell polarity. The FAT-related cadherins are characterized by a large number of cadherin repeats (34 in FAT and 27 in dachsous). Their cytoplasmic domains can bind to catenins. T- (=truncated-)cadherin differs from other cadherins in that it has no transmembrane domain but is attached to the cell membrane via a glycosylpho-sphatidylinositol anchor. 

A process in which a substance gains entry into a cell. Endocytic mechanisms are crucial for a variety of cellular functions such as the uptake of nutrients, regulation of cell surface expression of receptors, maintenance of cell polarity, and more. Receptor-mediated endocytosis via clathrin-coated pits is the most studied endocytic process, which is important for regulation of the time and magnitude of signals generated by a variety of cell-surface receptors. 

Wnt/non-P-catenin signaling is not as well characterized biochemically as the Wnt/p-catenin-dependent pathway this may reflect that it is molecularly more diverse, at least in vertebrates. In Drosophila the best characterized Wnt/non-P-catenin pathway is planar cell polarity (PCP) signaling. Ironically, although it certainly depends on a Fz receptor, it remains... 

Nelson, W.J. Hammerton, R.W. (1989). A membrane-cytoskeletal complex containing Na, K -AT-Pase, ankyrin, and fodrin in Madin-Darby canine kidney (MDCK cells) Implications for the biogenesis of epithelial cell polarity. J. Cell Biol. 108, 893-902. 

Intracellular motility is also of vital importance in the lives of cells and the organisms they form. Material and organelles are transported within cells along microtubules and microfilaments an extreme example of this are the axons of nerve cells which transport materials to the synapses where they are secreted—another motile event. Other examples of intracellular motility include phagocytosis, pino-cytosis, the separating of chromosomes and cells in cell division, and maintenance of cell polarity. 

PAMPs and various tissue factors can prime DCs to produce T-cell-polarizing factors [21], IL-12 is a pro-inflammatory cytokine that induces IFN-y and promotes the development of Thl-cell differentiation [31], Other Thl-polarizing factors are IFN-a and IFN-(3 [32] and cell-surface expressed intracellular adhesion molecule (ICAM)-l [33]. On the other hand, it has been shown that NF-kB inducing kinase (NIK), which is known to regulate B-cell maturation and lymphoid organogenesis, is important for the induction of Thl7 cells [34],... 

Janeway CA Jr, Medzhitov R Innate immune recognition. Armu Rev Immunol 2002 20 197-216. Kapsenberg ML Dendritic-cell control of pathogen-driven T-cell polarization. Nat Rev Immunol 2003 3 984-993. 

A third justifreation for studying the eell eycle of this yeast is that it afiords a convenient system in which to study cell polarity. Together with asymmetric cell division (irrherent in the S. cerevisiae cell cyele with the unequal sized mothers and daughters), the development of polarity is emeial in many aspects of development and differentiation. Furthermore, as explained in more detail later in this chapter, the correct... 

Shimonaka M, Katagiri K, Nakayama T, et al. Rapl translates chemokine signals to integrin activation, cell polarization, and motility across vascular endothelium under flow. J Cell Biol 2003 161 (2) 417 427. 

CCR4 and CCR8 have been described as receptors preferentially expressed on Th2 cells (58,69,72,79,80). Just as for the Thl-associated chemokine receptors, despite the strong preferential association of CCR4 and CCR8 with Th2 cells, there is no evidence that these Th2-associated receptors are necessary for Th2 cell polarization (60,81). 

Kim CH, Rott L, Kunkel EJ, et al. Rules of chemokine receptor association with T cell polarization in vivo. J Clin Invest 2001 108 1331-1339. 

Raff What about the asymmetric divisions in the mesoderm Where is the cell polarity originating ... 

Cell polarity and anaphase spindle positioning in the wild-type one-cell stage C. elegans embryo... 

Simon What determines the initial cell polarity ... 

Etemad-Moghadam B, Guo S, Kemphues KJ 1995 Asymmetrically distributed PAR-3 protein contributes to cell polarity and spindle alignment in early C. elegans embryos. Cell 83 743-752... 

R Kinne. Epithelial transport The interplay between ion gradients and cell polarity. In F Alvarado, CH van Os, eds. Ion Gradient-Coupled Transport. Inserm Symposium No. 26. New York Elsevier, 1986, pp 255-264. 

Fig. 6.3. Electron micrograph revealing the location of larvae in polarized Caco-2 monolayers grown on filter inserts (ManWarren etal., 1997). Apical microvilli provide evidence of epithelial cell polarization. Epithelial cell cytoplasm is evident above and below the larva. Bar = 2 pm. The position of the filter substrate is marked (F). Photomicrograph prepared by S. Pearce-Kelling and J. Ailing, Cornell University. 

Matter, K, and Mellman, I. (1994). Mechanisms of cell polarity sorting and transport in epithelial cells. Curr. Opin. CeU Biol. 6, 545—554. 

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