|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 113, Issue 2 303-313, Copyright © 2000 by Company of Biologists
JOURNAL ARTICLES |
G Ramm, L Pond, C Watts and W Stoorvogel
Department of Cell Biology, University Medical Center and Institute for Biomembranes, Utrecht University, The Netherlands.
Newly synthesized major histocompatibility complex class II molecules (MHC-II) are transported to MHC-II-containing endosomal and lysosomal compartments (MIICs) for the degradation of associated invariant chain and peptide loading. Subsequently MHC-II is transported to the plasma membrane, in part through direct fusion of MIICs with the plasma membrane. In search of potential alternative pathway(s) we studied the 3-dimensional structure of MIICs and the subcellular distribution of MHC-II by immuno electronmicroscopy on whole-mount preparations and cryosections of Mel JuSo cells. Intracellular MHC-II and invariant chain mainly localized to lamp-1 positive compartments suggesting that the majority of MHC-II exits the endocytic tract at lysosomes. Clathrin-coated lattices and buds were found to be associated with these organelles, but MHC-II was not found to be enriched in the clathrin-coated domains. Moreover, leupeptin, a drug that interferes with Ii-processing and delays delivery of newly synthesized MHC-II to the plasma membrane, was not found to decrease the relative amount of MHC-II in clathrin-coated areas. Together these data indicate clathrin-mediated exit site(s) from lysosomes but suggest that they do not selectively recruit mature MHC-II, consistent with the notion that transport to the plasma membrane occurs independently of the cytoplasmic domains of the MHC-II (&agr;) and (beta) chains.
This article has been cited by other articles:
![]() |
R. Wubbolts, R. S. Leckie, P. T. M. Veenhuizen, G. Schwarzmann, W. Mobius, J. Hoernschemeyer, J.-W. Slot, H. J. Geuze, and W. Stoorvogel Proteomic and Biochemical Analyses of Human B Cell-derived Exosomes. POTENTIAL IMPLICATIONS FOR THEIR FUNCTION AND MULTIVESICULAR BODY FORMATION J. Biol. Chem., March 21, 2003; 278(13): 10963 - 10972. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Kleijmeer, G. Ramm, D. Schuurhuis, J. Griffith, M. Rescigno, P. Ricciardi-Castagnoli, A. Y. Rudensky, F. Ossendorp, C. J.M. Melief, W. Stoorvogel, et al. Reorganization of multivesicular bodies regulates MHC class II antigen presentation by dendritic cells J. Cell Biol., October 1, 2001; 155(1): 53 - 64. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Sachse, S. Urbe, V. Oorschot, G. J. Strous, and J. Klumperman Bilayered Clathrin Coats on Endosomal Vacuoles Are Involved in Protein Sorting toward Lysosomes Mol. Biol. Cell, April 1, 2002; 13(4): 1313 - 1328. [Abstract] [Full Text] [PDF] |
||||