|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
CELL SCIENCE AT A GLANCE |
Dept of Pharmacology, University of Colorado Health Science Center, 4200 E. 9th Ave, Denver, CO 80262, USA
In mammalian cells, cargo can be endocytosed via clathrin-coated pits, the clathrin-independent pathway or caveolae. In yeast cells the morphology of the internalization step is not yet defined. All internalization pathways lead to the appearance of cargo in the peripheral early endosomes. Coated vesicles must be at least partially uncoated to fuse with early endosomes. Early endosomes then undergo homotypic fusion. From early endosomes cargo is recycled back to the plasma membrane, sorted to the late recycling compartment or delivered to late endosomes (the prelysosomal compartment or prevacuole) by means of carrier vesicles or through a ‘maturation’ process (a change in biochemical composition and morphology). Carrier vesicles and late endosomes often display a morphology typical of multi-vesicular bodies, which contain internal membrane structures. These structures appear to be formed by invagination of the endosomal membrane. Late endosomes either mature into lysosomes or transfer cargo to lysosomes through vesicular intermediates. The recycling compartment is responsible for delivery of the cargo back to the cell surface. The endosome/lysosome system can send to and receive cargo from the trans-Golgi network (TGN) via vesicular intermediates. Routes of internalization and intracellular trafficking are shown by black arrows and labelled in black.
The figure shows the major proteins involved in regulation of endocytic pathways. Mammalian proteins are in shown in red, and yeast proteins are shown in green. Where the mammalian and yeast protein have the same name, this is given in green (AP-3, Vps17p, 26p, 29p, 35p) or red (GGAs). Organelles are labelled in blue, with the exception of yeast-specific names, which are green. Protein-protein interaction (EH, Eps15 homology, PH, pleckstrin homology; SH3, SRC homology 3) domains are indicated. Closest mammalian and yeast homologs are separated by a solidus (/). Mammalian homologs of yeast proteins involved in the internalization step are actin (Act1p), calmodulin (Cmd1p), type I (unconventional) myosin (Myo5p); EH-containing proteins (Pan1p and End3p), amphyphysins (Rvs161p and Rvs167p), synaptojanin (Sjl1p), and the clathrin heavy and light chains (Chc1p and Clc1p, respectively). Proteins, for which biochemical, functional or genetic interactions have been demonstrated are shown in boxes. Each AP-1, AP-2 and AP-3 complex consists of four subunits: ß, µ and 
are highly homologous in all three complexes, whereas 
, 
and 
are specific for AP-1, AP-2 and AP-3, respectively. ß-arrestin can bind to clathrin and AP-2 and is involved in coated-pit recruitment of G-protein-coupled receptors. Lipids: PPIs, polyphosphoinositides; PtdIns, phosphatidylinositol; PtdIns(3)P, PtdIns 3-phosphate; PtdIns(3,5)P2, PtdIns 3,5-bisphosphate; PtdIns(5)Ps, PtdIns phosphates phosphorylated at position 5; PtdInsPs, PtdIns(5)Ps in which the phosphate has been removed from position 5. Other abbreviations: NSF, N-ethylmaleimide-sensitive factor; v- and t-SNARE, vesicular- and target-membrane soluble NSF attachment protein receptors. Vps, vacuolar protein sorting.
|
This article has been cited by other articles:
|
|
 |
|
  A. Ignatiuk, J. P. Quickfall, A. D. Hawrysh, M. D. Chamberlain, and D. H. Anderson The Smaller Isoforms of Ankyrin 3 Bind to the p85 Subunit of Phosphatidylinositol 3'-Kinase and Enhance Platelet-derived Growth Factor Receptor Down-regulation J. Biol. Chem., March 3, 2006; 281(9): 5956 - 5964. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Tsacoumango, S. J. Kil, L. Ma, F. D. Sonnichsen, and C. Carlin A novel dileucine lysosomal-sorting-signal mediates intracellular EGF-receptor retention independently of protein ubiquitylation J. Cell Sci., September 1, 2005; 118(17): 3959 - 3971. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D.-W. Shen, X.-J. Liang, M. A. Gawinowicz, and M. M. Gottesman Identification of Cytoskeletal [14C]Carboplatin-Binding Proteins Reveals Reduced Expression and Disorganization of Actin and Filamin in Cisplatin-Resistant Cell Lines Mol. Pharmacol., October 1, 2004; 66(4): 789 - 793. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Wherlock, A. Gampel, C. Futter, and H. Mellor Farnesyltransferase inhibitors disrupt EGF receptor traffic through modulation of the RhoB GTPase J. Cell Sci., July 1, 2004; 117(15): 3221 - 3231. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Treusch, S. Knuth, S. A. Slaugenhaupt, E. Goldin, B. D. Grant, and H. Fares Caenorhabditis elegans functional orthologue of human protein h-mucolipin-1 is required for lysosome biogenesis PNAS, March 30, 2004; 101(13): 4483 - 4488. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Liu and J. I. Shapiro Endocytosis and Signal Transduction: Basic Science Update Biol Res Nurs, October 1, 2003; 5(2): 117 - 128. [Abstract] [PDF]
|
|
|
|
 |
|
 H. Resat, J. A. Ewald, D. A. Dixon, and H. S. Wiley An Integrated Model of Epidermal Growth Factor Receptor Trafficking and Signal Transduction Biophys. J., August 1, 2003; 85(2): 730 - 743. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Otsuki, T. Itoh, and T. Takenawa Neural Wiskott-Aldrich Syndrome Protein Is Recruited to Rafts and Associates with Endophilin A in Response to Epidermal Growth Factor J. Biol. Chem., February 14, 2003; 278(8): 6461 - 6469. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Fazi, M. J. T. V. Cope, A. Douangamath, S. Ferracuti, K. Schirwitz, A. Zucconi, D. G. Drubin, M. Wilmanns, G. Cesareni, and L. Castagnoli Unusual Binding Properties of the SH3 Domain of the Yeast Actin-binding Protein Abp1. STRUCTURAL AND FUNCTIONAL ANALYSIS J. Biol. Chem., February 8, 2002; 277(7): 5290 - 5298. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
