![[Feedback]](/icons/banner/feedbackACT.gif){kind=icon}
![[For Subscribers]](/icons/banner/subscriberACT.gif){kind=icon}
![[Archive]](/icons/banner/archiveACT.gif){kind=icon}
![[Search]](/icons/banner/searchACT.gif){kind=icon}
![[Contents]](/icons/banner/tocACT.gif){kind=icon}
|
|
|
|
|
||
Vol. 9, Issue 2, 497-511, February 1998
Department of Molecular Genetics & Cell Biology, The University of
Chicago, Chicago, Illinois 60637
Formation and discharge of dense-core secretory vesicles depend on
controlled rearrangement of the core proteins during their assembly and
dispersal. The ciliate Tetrahymena thermophila offers a
simple system in which the mechanisms may be studied. Here we show that
most of the core consists of a set of polypeptides derived proteolytically from five precursors. These share little overall amino
acid identity but are nonetheless predicted to have structural similarity. In addition, sites of proteolytic processing are notably conserved and suggest that specific endoproteases as well as
carboxypeptidase are involved in core maturation. In vitro binding
studies and sequence analysis suggest that the polypeptides bind
calcium in vivo. Core assembly and postexocytic dispersal are
compartment-specific events. Two likely regulatory factors are
proteolytic processing and exposure to calcium. We asked whether these
might directly influence the conformations of core proteins. Results
using an in vitro chymotrypsin accessibility assay suggest that these
factors can induce sequential structural rearrangements. Such
progressive changes in polypeptide folding may underlie the mechanisms
of assembly and of rapid postexocytic release. The parallels between dense-core vesicles in different systems suggest that similar mechanisms are widespread in this class of organelles.
This article has been cited by other articles:
|
|
 |
|
  A. T. Cowan, G. R. Bowman, K. F. Edwards, J. J. Emerson, and A. P. Turkewitz Genetic, Genomic, and Functional Analysis of the Granule Lattice Proteins in Tetrahymena Secretory Granules Mol. Biol. Cell, September 1, 2005; 16(9): 4046 - 4060. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Stemm-Wolf, G. Morgan, T. H. Giddings Jr., E. A. White, R. Marchione, H. B. McDonald, and M. Winey Basal Body Duplication and Maintenance Require One Member of the Tetrahymena thermophila Centrin Gene Family Mol. Biol. Cell, August 1, 2005; 16(8): 3606 - 3619. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. R. Bradshaw, N. D. Chilcoat, J. W. Verbsky, and A. P. Turkewitz Proprotein Processing within Secretory Dense Core Granules of Tetrahymena thermophila J. Biol. Chem., January 31, 2003; 278(6): 4087 - 4095. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Touz, N. Gottig, T. E. Nash, and H. D. Lujan Identification and Characterization of a Novel Secretory Granule Calcium-binding Protein from the Early Branching Eukaryote Giardia lamblia J. Biol. Chem., December 20, 2002; 277(52): 50557 - 50563. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Haddad, G. R. Bowman, and A. P. Turkewitz New Class of Cargo Protein in Tetrahymena thermophila Dense Core Secretory Granules Eukaryot. Cell, August 1, 2002; 1(4): 583 - 593. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. D. Chilcoat, N. C. Elde, and A. P. Turkewitz An antisense approach to phenotype-based gene cloning in Tetrahymena PNAS, June 28, 2001; (2001) 151243498. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L Vayssie, N Garreau de Loubresse, and L Sperling Growth and form of secretory granules involves stepwise assembly but not differential sorting of a family of secretory proteins in Paramecium J. Cell Sci., January 3, 2001; 114(5): 875 - 886. [Abstract] [PDF]
|
|
|
|
|
|
R. Kuliawat, D. Prabakaran, and P. Arvan Proinsulin Endoproteolysis Confers Enhanced Targeting of Processed Insulin to the Regulated Secretory Pathway Mol. Biol. Cell, June 1, 2000; 11(6): 1959 - 1972. [Abstract] [Full Text]
|
|
|
|
|
|
N. D. Chilcoat, N. C. Elde, and A. P. Turkewitz An antisense approach to phenotype-based gene cloning in Tetrahymena PNAS, July 17, 2001; 98(15): 8709 - 8713. [Abstract] [Full Text] [PDF]
|
|
