Document Detail


Conjugation rescue of an exocytosis-competent membrane microdomain in Tetrahymena thermophila mutants.
MedLine Citation:
PMID:  3464949     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Conjugation-rescue experiments with two Tetrahymena thermophila mutants (exo-) incapable of exocytosis (SB255, SB258) have been used to dissect regulatory steps in assembly of a functional membrane microdomain, the fusion rosette. "Rescue" refers to the recovery of a secretory activity. Exo- mutants fail to secrete mucus normally (form capsules) when stimulated by the secretagogue alcian blue and are blocked before the assembly of a functional fusion rosette in the cell membrane. Two criteria are used to assay recovery of the wild-type (exo+) phenotype: the conjugant's ability to form capsules when stimulated and the presence of assembled rosettes, which disperse upon stimulation. Conjugation of exo+ X SB258 results in restoration of secretion in 60% of the mutant conjugants and reappearance of assembled rosettes. Secretory capacity is restored in the SB258 cell within one-half hour of firm pair formation. This restoration is not due to new gene expression or continued protein synthesis, since it occurs when SB258 is crossed to a "star" strain (A*), which has defective micronuclei and therefore cannot contribute wild-type genes, and restoration occurs in the presence of cycloheximide during conjugation. Conjugation of exo+ X SB255 reveals a real but inefficient restoration of exocytic capacity in the exo- conjugant and a significant decrease of exocytic capacity in the exo+ conjugant. SB255 X SB258 crosses also show a low but significant rescue of exocytic competence, indicating that different components of the exocytic mechanism are affected in the two mutants. This cross leads to restoration of rosette assembly and function in one of the partners, presumably SB258. These results provide data about some of the steps necessary for rosette assembly and suggest that transferable factors that promote and/or inhibit exocytosis are present in these cells.
Authors:
B H Satir; M Reichman; E Orias
Related Documents :
2473079 - Cyclic amp enhances the sexual agglutinability of chlamydomonas flagella.
18556249 - Expression of egfl7 in primordial germ cells and in adult ovaries and testes.
21245959 - Su5416 induces premature senescence in endothelial progenitor cells from patients with ...
21414589 - New insights into vinculin function and regulation.
21424539 - Reactive oxygen species mediate high glucose-induced heparanase-1 production and hepara...
21438539 - Hydroxytyrosol induces proliferation and cytoprotection against oxidative injury in vas...
16497699 - Indices of low-grade chronic inflammation in polycystic ovary syndrome and the benefici...
12056849 - Ultrastructural localization of type vi collagen in normal adult and osteoarthritic hum...
12445069 - Allopurinol and superoxide dismutase protect against leucocyte-endothelium interactions...
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Proceedings of the National Academy of Sciences of the United States of America     Volume:  83     ISSN:  0027-8424     ISO Abbreviation:  Proc. Natl. Acad. Sci. U.S.A.     Publication Date:  1986 Nov 
Date Detail:
Created Date:  1986-12-05     Completed Date:  1986-12-05     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  7505876     Medline TA:  Proc Natl Acad Sci U S A     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  8221-5     Citation Subset:  IM    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Cell Membrane / ultrastructure
Conjugation, Genetic*
Cycloheximide / pharmacology
Exocytosis*
Freeze Fracturing
Mutation
Tetrahymena / genetics*,  metabolism
Grant Support
ID/Acronym/Agency:
GM27298/GM/NIGMS NIH HHS; GM32767/GM/NIGMS NIH HHS; P30-CA 1-3330/CA/NCI NIH HHS
Chemical
Reg. No./Substance:
66-81-9/Cycloheximide
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Protein tyrosine phosphorylation in the cell cycle of BALB/c 3T3 fibroblasts.
Next Document:  Antibodies to liver cell adhesion molecule perturb inductive interactions and alter feather pattern ...