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Competing proteins

  1. Jan 20, 2015 #1
    Are proteins in our body competition with each other? It is known that bacteria in our intestines compete, but regarding proteins I only found here:

    "RNA transcripts, both protein-coding and non-coding, thus have the ability to compete for microRNA binding and co-regulate each other in complex ceRNA networks (ceRNETs)"

    Does anyone know more competition in our body?
     
  2. jcsd
  3. Jan 20, 2015 #2

    Pythagorean

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    Yes, proteins have many mechanisms through which they "compete" or to be more specific, regulate one another in an inhibitory way, but they can also activate one another. Phosphorylation and methylation are the examples I know of. Elsewhere in biology, agonists can compete with partial agonists to bind with receptors and inhibitory signals in the brain compete with excitatory signals (through opposing charge displacement). Systems can compete - this is the mechanism of the sympathetic vs. parasympathetic system. In a flight-or-fight situation, sympathetic system floods the body with adrenaline and noradrenaline, which prepares the body for high-demand physical activity. Once the danger is apparently gone, the parasympathetic system returns the body to a rest state, primarily through acetylcholine.

    A lot of times, biologists use the analogy of a gas pedal and a break pedal - much of the function of the human body is made up of some analog of inhibitors and activators. Did you know that coffee doesn't actually press a gas pedal in your body, it lets off the break. That is, it blocks adenosine receptors; adenosine gradually builds in your body throughout the day, activating more and more adenosine receptors, making you more and more drowsy; coffee blocks that effect buy taking the place of adenosine on the receptors, but not activating it like adenosine does. Of course, coffee itself is a drug, not an endogenous chemical.
     
  4. Jan 21, 2015 #3
    "Yes, proteins have many mechanisms through which they "compete" or to be more specific, regulate one another in an inhibitory way"

    Is this competition?

    "Phosphorylation and methylation are the examples I know of."

    I know that methylation has something to do with DNA, and changes the expression of genes. Phosphorylation means, kind of in the same way, that f.i. enzymes are turned on/active. I don't really see the competition there.

    The coffee examples is a matter of choice, because you can either drink it or not (but franctly I don't have a choice anymore, it seems, because I drink coffee every morning, and I get a headache when I don't, but there is a personal choice involved. Just like smoking, which causes methylation, you can either smoke or not), but the flight-or-fight situation example shows that moment one type of molecules are extreted, and the other moment different molecules are. These molecules are not in competition with each other, are they/ And the sites that take up the molecules don't really have a choice, so I don't know if this is called 'competition'.

    In fish (in this case salmon and trout) it seems to me (I read here) that the females are even more active:

    "We found that activating sperm in ovarian fluid makes them live about twice as long as in river water. Importantly, both species' sperm also switch from swimming in tight elliptical circles in river water, to swimming in straightened trajectories in ovarian fluid. This behaviour allows sperm to navigate towards the egg by following a chemical cue".

    I'd like to know if proteins are, in the same way like the above examples, are considered 'in competition' which each other.
     
  5. Jan 21, 2015 #4

    Pythagorean

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    Phosphorylation is not competitive itself, it is a mechanism by which competition can happen between proteins. When it does happen, it's called "competitive phosphorylation", but phosphorylation can also be cooperative.

    The parasympathetic and sympthatetic nervous systems affect the whole body. In some places, they compete and in other places, they cooperate:

    http://www.dartmouth.edu/~rswenson/NeuroSci/chapter_3.html
     
    Last edited: Jan 21, 2015
  6. Jan 24, 2015 #5
    So what do you think about competition for a binding site that either leads to a healthy body, or to cancer (article here)

    "There is competition for binding to FGFR2 and one of the two competitors, phospholipase Cγ1 (Plcγ1), will increase cancer cell metastasis. The other protein inhibits the opportunity for this to occur," said John Ladbury, Ph.D., professor of Biochemistry and Molecular Biology.
     
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