|
|
|
|
|
|
|
|
|||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
Journal of Cell Science, Vol 108, Issue 4 1761-1769, Copyright © 1995 by Company of Biologists
JOURNAL ARTICLES |
SD Redick and JE Schwarzbauer
Department of Molecular Biology, Princeton University, NJ 08544, USA.
Tenascin, an extracellular matrix protein that modulates cell adhesion, exists as a unique six-armed structure called a hexabrachion. The human hexabrachion is composed of six identical 320 kDa subunits and the structure is stabilized by inter-subunit disulfide bonds between amino-terminal segments. We have examined the biosynthesis of tenascin and its assembly into hexabrachions using pulsechase labeling of U-138 MG human glioma cells. Newly synthesized tenascin hexamers are secreted within 60 minutes of translation initiation. Intracellularly, as early as full length tenascin can be detected in pulse-labeled cell lysates, it is already in hexameric form. No precursors, such as monomers, dimers, or trimers, were identified that could be chased into hexamers. This lack of assembly intermediates suggests that nascent tenascin polypeptides associate prior to completion of translation. In contrast, fibronectin monomers in the same lysates are gradually formed into disulfide-bonded dimers. Although hexamer assembly is rapid, the rate-limiting step in secretion appears to be transport to the medial Golgi as endoglycosidase H-resistance was not detected until after a 30 minute chase. These results provide evidence for a novel co-translational mechanism of tenascin assembly which would be facilitated by its length and by the amino-terminal location of the assembly domain.
This article has been cited by other articles:
|
|
 |
|
  R. Suetterlin, W. Baschong, and R. H. Laeng Immunofluorescence and Confocal Laser Scanning Microscopy of Chronic Myeloproliferative Disorders on Archival Formaldehyde-fixed Bone Marrow J. Histochem. Cytochem., March 1, 2004; 52(3): 347 - 354. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. M. Ritty, T. Broekelmann, C. Tisdale, D. M. Milewicz, and R. P. Mecham Processing of the Fibrillin-1 Carboxyl-terminal Domain J. Biol. Chem., March 26, 1999; 274(13): 8933 - 8940. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Kammerer, T. Schulthess, R. Landwehr, A. Lustig, D. Fischer, and J. Engel Tenascin-C Hexabrachion Assembly Is a Sequential Two-step Process Initiated by Coiled-coil alpha -Helices J. Biol. Chem., April 24, 1998; 273(17): 10602 - 10608. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. A. Luczak, S. D. Redick, and J. E. Schwarzbauer A Single Cysteine, Cys-64, Is Essential for Assembly of Tenascin-C Hexabrachions J. Biol. Chem., January 23, 1998; 273(4): 2073 - 2077. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. N. Fedorov and T. O. Baldwin Cotranslational Protein Folding J. Biol. Chem., December 26, 1997; 272(52): 32715 - 32718. [Full Text] [PDF]
|
|
|
|
|
|
R. L. Haynes, T. Zheng, and C. V. Nicchitta Structure and Folding of Nascent Polypeptide Chains during Protein Translocation in the Endoplasmic Reticulum J. Biol. Chem., July 4, 1997; 272(27): 17126 - 17133. [Abstract] [Full Text] [PDF]
|
|
