Related Experiment Videos
Localization of membrane protein synthesized after infection with bacteriophage T4
Abstract:
The synthesis of membrane protein after infection with bacteriophage T4 was examined. Protein constituents of both the cytoplasmic and outer membrane are made during the infective cycle. In addition, newly synthesized membrane protein is found in material which has a buoyant density greater than that of either of the two host membrane fractions. Polyacrylamide gel analyses and solubilization studies using the detergent Sarkosyl indicate that synthesis of most of the membrane proteins made during the first 5 min of infection is directed by bacterial genes. New membrane proteins synthesized at times greater than 6 min after infection appear to be distinct from those of the host, and new proteins of the outer membrane are different from those of the inner. Proteins in the new dense membrane fraction are similar to those of the outer membrane.
Insights
Bacteriophage T4 infection triggers synthesis of new bacterial membrane proteins, with early synthesis directed by host genes and later synthesis by viral genes, forming distinct outer and inner membrane proteins.
Area of Science:
- Microbiology
- Molecular Biology
- Virology
Background:
- Bacteriophage T4 infects bacteria, altering host cell processes.
- Membrane proteins are crucial for bacterial cell structure and function.
Purpose of the Study:
- To investigate the synthesis of membrane proteins during bacteriophage T4 infection.
- To determine the genetic control and characteristics of newly synthesized membrane proteins.
Main Methods:
- Analysis of protein synthesis post-bacteriophage T4 infection.
- Buoyant density centrifugation to separate membrane fractions.
- Polyacrylamide gel electrophoresis and Sarkosyl solubilization studies.
Main Results:
- Both cytoplasmic and outer membrane proteins are synthesized during infection.
- Newly synthesized membrane proteins exist in a fraction with higher buoyant density.
- Early protein synthesis (0-5 min) is primarily directed by bacterial genes.
- Later protein synthesis (>6 min) involves new proteins distinct from host proteins, with unique outer and inner membrane proteins.
- Proteins in the dense fraction resemble outer membrane proteins.
Conclusions:
- Bacteriophage T4 infection redirects bacterial membrane protein synthesis.
- Distinct sets of membrane proteins are synthesized at different stages of infection.
- New membrane protein fractions suggest specific assembly or localization pathways.