Related Experiment Videos
A 57-kilodalton protein associated with Spiroplasma melliferum fibrils undergoes reversible phosphorylation
M W Platt1, J Reizer, S Rottem
1Department of Membrane and Ultrastructure Research, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Abstract:
Phosphorylation of a major 57-kilodalton protein substrate was observed in cell lysates of Spiroplasma melliferum BC3 incubated with [gamma-32P]ATP. Only serine phosphates have been isolated from the acid hydrolysate of the phosphorylated protein. The 57-kilodalton protein substrate was found, to a large extent, in the cytosolic fraction and, to a lesser extent, associated with cell membranes and was detected in the Triton X-100-insoluble fraction that contained fibrils.
Insights
Spiroplasma melliferum BC3 exhibits protein phosphorylation, specifically on a 57-kilodalton protein substrate. This phosphorylation occurs at serine residues, with the protein found in the cytosol and associated with cell membranes.
Area of Science:
- Microbiology
- Biochemistry
- Cell Biology
Background:
- Spiroplasma melliferum is a bacterium with unique cellular characteristics.
- Protein phosphorylation is a key regulatory mechanism in cellular processes.
Purpose of the Study:
- To investigate protein phosphorylation in Spiroplasma melliferum BC3.
- To identify the specific protein substrate and phosphorylation site.
Main Methods:
- Incubation of Spiroplasma melliferum BC3 cell lysates with [gamma-32P]ATP.
- Isolation and analysis of phosphorylated protein from acid hydrolysate.
- Fractionation of cell lysates to determine protein localization.
Main Results:
- A major 57-kilodalton protein substrate was phosphorylated in Spiroplasma melliferum BC3.
- Phosphorylation occurred exclusively at serine residues.
- The 57-kilodalton protein was primarily located in the cytosol, with smaller amounts associated with cell membranes and insoluble fibrils.
Conclusions:
- Spiroplasma melliferum BC3 possesses a serine kinase activity targeting a 57-kilodalton protein.
- This protein's localization suggests roles in both cytosolic functions and membrane-associated processes, potentially including cytoskeletal elements.