Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.3.3.1 (citrate synthase)
 4,488 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tetrahymena 14-nm filament-forming protein has dual functions as a citrate synthase in mitochondria and as a cytoskeletal protein involved in oral morphogenesis and in pronuclear behavior during conjugation. By immunoblotting using monoclonal and polyclonal antibodies following two-dimensional gel electrophoresis, we demonstrated that the 14-nm filament protein fraction contained two 49-kDa proteins whose isoelectric points were 8.0 and 9.0; a monoclonal antibody (MAb) 26B4 and a polyclonal antibody 49KI reacted only to a pI 8.0 protein, while two other MAbs, 11B6 and 11B8, reacted only to a pI 9.0 protein. From the N-terminal amino acid sequences, the pI 8.0 protein was identified as the previously reported 14-nm filament-forming protein/citrate synthase, but the pI 9.0 protein N-terminal sequence had no similarity with that of the pI 8.0 protein. The pI 9.0 protein is considered to be a 14-nm filament-associated protein since the pI 9.0 protein copurifies with the pI 8.0 protein during two cycles of an assembly and disassembly purification protocol. Cloning and sequencing the pI 9.0 protein gene from a Tetrahymena pyriformis cDNA library, we identified the pI 9.0 protein as elongation factor 1 alpha (EF-1 alpha) based on it sharing 73-76% sequence identity with EF-1 alpha from several species.
 ...
PMID:Identification of Tetrahymena 14-nm filament-associated protein as elongation factor 1 alpha. 138 89

Tetrahymena 14-nm filament protein has been shown to have dual functions as a citrate synthase in mitochondria and as a cytoskeletal protein in oral morphogenesis and pronuclear behavior during conjugation. Immunofluorescence studies of the 14-nm filament protein/citrate synthase in mitochondria found that intense mitochondrial fluorescence remained unchanged in Tetrahymena cells taken from logarithmic growth phase to stationary phase. However, electron microscopic studies showed that electron-dense rod-shaped structures found in mitochondrial matrices tended to increase in Tetrahymena cells in the growth decline phase. The rods were composed of side-by-side straight filaments with diameters of approximately 14 to 16 nm. Serial sections revealed that in Tetrahymena cells in growth decline phase, one to four electron-dense rods existed in the matrices of every mitochondrion. Immunoelectron microscopy using an anti-14-nm filament antibody clearly showed that a filament bundle of the electron-dense rod was the bundle of polymerized filaments of 14-nm filament protein/citrate synthase. These results strongly suggest that dynamic monomer-polymer conversion of the 14-nm filament protein/citrate synthase in mitochondria depends upon the physiological conditions of Tetrahymena cells.
 ...
PMID:Tetrahymena intramitochondrial filamentous inclusions contain 14-nm filament protein/citrate synthase. 773 52

One gene encoding a protein has been shown to have two entirely different functions. Such a phenomenon, which has been called "gene sharing," was first known in crystallins. We found two multifunctional proteins in the ciliated protozoan Tetrahymena: 14-nm filament protein and protein translation elongation factor 1-alpha (EF-1 alpha). The 14-nm filament protein has dual functions as a citrate synthase in mitochondria and as a cytoskeletal protein in cytoplasm. In cytoplasm, the 14-nm filament protein was involved in oral morphogenesis and in pronuclear behavior during conjugation. The observation that Tetrahymena intramitochondrial filamentous inclusions contain the 14-nm filament protein and that the citrate synthase activity of the 14-nm filament protein is decreased by polymerization and increased by depolymerization, suggests a possible modulating mechanism of citrate synthase activity by monomer-polymer conversion in mitochondria in situ. The EF-1 alpha functions as an F-actin-bundling protein and a 14-nm filament-associated protein as well as an elongation factor in protein synthesis. The F-actin-bundling activity of EF-1 alpha was regulated by Ca2+ and calmodulin. Here we review the properties and functions of two multifunctional proteins in Tetrahymena.
 ...
PMID:Multifunctional proteins in Tetrahymena: 14-nm filament protein/citrate synthase and translation elongation factor-1 alpha. 857 89