Membrane-enclosed crystals in Dictyostelium discoideum cells, consisting of developmentally regulated proteins with sequence similarities to known esterases.

Details

Serval ID
serval:BIB_7B51D70C55D3
Type
Article: article from journal or magazin.
Collection
Publications
Title
Membrane-enclosed crystals in Dictyostelium discoideum cells, consisting of developmentally regulated proteins with sequence similarities to known esterases.
Journal
Journal of Cell Biology
Author(s)
Bomblies L., Biegelmann E., Döring V., Gerisch G., Krafft-Czepa H., Noegel A.A., Schleicher M., Humbel B.M.
ISSN
0021-9525 (Print)
ISSN-L
0021-9525
Publication state
Published
Issued date
1990
Volume
110
Number
3
Pages
669-679
Language
english
Abstract
Developing cells of Dictyostelium discoideum contain crystalline inclusion bodies. The interlattice spaces of the crystals are approximately 11 nm, and their edge dimensions vary in aggregating cells from 0.1 to 0.5 micron. The crystals are enclosed by a membrane with the characteristics of RER. To unravel the nature of the crystals we isolated them under electron microscopical control and purified the two major proteins that cofractionate with the crystals, one of an apparent molecular mass of 69 kD, the other of 56 kD. This latter protein proved to be identical with the protein encoded by the developmentally regulated D2 gene of D. discoideum, as shown by its reactivity with antibodies raised against the bacterially expressed product of a D2 fusion gene. The D2 gene is known to be strictly regulated at the transcript level and to be controlled by cAMP signals. Accordingly, very little of the 56-kD protein was detected in growth phase cells, maximal expression was observed at the aggregation stage, and the expression was stimulated by cAMP pulses. The 69-kD protein is the major constituent of the crystals and is therefore called "crystal protein." This protein is developmentally regulated and accumulates in aggregating cells similar to the D2 protein, but is not, or is only slightly regulated by cAMP pulses. mAbs specific for either the crystal protein or the D2 protein, labeled the intracellular crystals as demonstrated by the use of immunoelectron microscopy. The complete cDNA-derived amino acid sequence of the crystal protein indicates a hydrophobic leader and shows a high degree of sequence similarity with Torpedo acetylcholinesterase and rat lysophospholipase. Because the D2 protein also shows sequence similarities with various esterases, the vesicles filled with crystals of these proteins are named esterosomes.
Keywords
Amino Acid Sequence, Antibodies, Monoclonal/diagnostic use, Base Sequence, Cloning, Molecular, DNA, Fungal/genetics, DNA, Fungal/isolation & purification, Dictyostelium/enzymology, Dictyostelium/growth & development, Esterases/genetics, Fungal Proteins/genetics, Fungal Proteins/isolation & purification, Intracellular Membranes/ultrastructure, Microscopy, Electron, Microscopy, Fluorescence, Molecular Sequence Data, Molecular Weight, Organelles/enzymology, Organelles/ultrastructure, Protein Conformation, Protozoan Proteins, Restriction Mapping, Sequence Homology, Nucleic Acid
Pubmed
Web of science
Open Access
Yes
Create date
18/10/2012 13:08
Last modification date
20/08/2019 14:37
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