Forget Gene Expression: Protein Expression Controlled Via Several Different Mechanisms

Working with the African clawed frog (Xenpous laevis), researchers discovered that "levels of specific proteins did not always correspond to levels of the mRNAs that code for them, confirming that protein expression is controlled via several different mechanisms." Might one of the mechanisms be the 2nd Law of Thermodynamics, the hypothesis reported here?

Leap forward for development proteomics
Published: Mar 31, 2014

……Dovichi and his colleagues were able to identify and measure changes in the concentration of nearly 4000 different proteins, reporting their findings in Scientific Reports. As expected, the expression of these proteins changed in step with key events in the physiological development of the X. laevis embryo, with the majority of the proteins involved in biological processes such as DNA replication, transcription and translation, energy generation, protein transport and protein folding. Less expected was the finding that levels of specific proteins did not always correspond to levels of the mRNAs that code for them, confirming that protein expression is controlled via several different mechanisms.

As well as showing how embryonic development normally occurs, this work could also reveal information about congenital birth defects caused by misregulation of gene expression and about the effects of disease on embryo development. ‘It's easy to manipulate the embryos to mimic certain disease states, making Xenopus extremely valuable to biologists,’ says team member Paul Huber.

The Research Article:

Quantitative proteomics of Xenopus laevis embryos: expression kinetics of nearly 4000 proteins during early development

While there is a rich literature on transcription dynamics during the development of many organisms, protein data is limited. We used iTRAQ isotopic labeling and mass spectrometry to generate the largest developmental proteomic dataset for any animal. Expression dynamics of nearly 4,000 proteins of Xenopus laevis was generated from fertilized egg to neurula embryo. Expression clusters into groups. The cluster profiles accurately reflect the major events that mark changes in gene expression patterns during early Xenopus development. We observed decline in the expression of ten DNA replication factors after the midblastula transition (MBT), including a marked decline of the licensing factor XCdc6. Ectopic expression of XCdc6 leads to apoptosis; temporal changes in this protein are critical for proper development. Measurement of expression in single embryos provided no evidence for significant protein heterogeneity between embryos at the same stage of development.

reply to post by soficrow


The second law of thermodynamics states that the entropy of an isolated system never decreases, because isolated systems always evolve toward thermodynamic equilibrium— a state depending on the maximum entropy.

en.wikipedia.org...


just in case people are wondering, better to state it rather then be inundated by people to lazy to google it themselves asking you "whats the 2nd law of thermodynamics?"

reply to post by pryingopen3rdeye


Thanks. Good thinking.

S&