Cracking open a cell biology mystery

Aug 09, 2010

Two billion years ago somewhere in the primordial soup, one of our single-cell ancestors made a quick lunch out of another. But, in a moment of evolutionary serendipity, the would-be prey worked out a "win-win" symbiotic deal with its predator, gaining a new home and becoming an indispensable source of energy renewal as well as taking on a host of other functions over time.

Although there are still many mysteries about the origin and function of these co-opted critters, which were given the name “mitochondria” (from the Greek words for “thread” and “granules”) in 1898, we now know that they are critical in cell respiration, cell death, and cellular homeostasis, and that many degenerative diseases have their roots in dysfunctions in any one or more of those tasks.

Perhaps one of the most interesting mitochondrial functions is also one of the least understood: the ability to uptake and regulate relatively massive amounts of calcium ions, a critical signaling molecule for a wide variety of cell processes, including metabolism. Although the biophysical properties of this calcium uptake are worked out, none of the proteins involved have been identified. Until now: A team of scientists from the Broad Institute, Massachusetts General Hospital/Harvard Medical School, and the University of Colorado, Boulder, describe the first gene (and its encoded protein) identified as central to the mitochrondrion’s uptake of calcium. The work appears in the August 8 advance online issue of Nature.

“Mitochondrial calcium uptake was first documented almost 50 years ago, but the proteins that drive this activity have remained one of the biggest mysteries in ,” said senior author Vamsi Mootha, associate professor a Harvard Medical School and Massachusetts General Hospital, and a senior associate member of the Broad Institute. “Our work identifies the first protein, which is now a ‘handle” by which to identify all the other proteins involved in this critical .”

To identify genes involved in mitochondrial calcium uptake, Mootha, first author Fabiana Perocchi, and their colleagues took advantage of previous biochemical work suggesting where to look for relevant proteins (i.e., the mitochondrion inner membrane) as well as the observation that yeast mitochondria did not have this particular calcium uptake trait that both mammalian and mammalian parasites share. Consulting MitoCarta -- an atlas of mitochondrial proteins recently developed at the Broad Institute -- they were able to prioritize eighteen candidate genes.

Turning to the powerful technology of RNA inhibition (RNAi), they then tested whether eliminating the function of each of these genes individually altered calcium uptake. One gene - MICU1 - emerged as a critical component of the calcium cycle. Although the gene itself had been identified previously by genome sequencing, its function was unknown. Subsequent experiments and analysis demonstrated that MICU1 plays a central role in coupling calcium fluxes in the cell cytosol to mitochondrial energy metabolism. Further studies already underway should reveal the precise molecular mechanisms by which MICU1 accomplishes its task, providing insight not only into mitochondrial function but also the diseases that are associated with its compromise.

Explore further: Researchers discover new strategy germs use to invade cells

More information: Perocchi et al. (2010). MICU1 encodes a mitochondrial EF hand protein required for Ca2+ uptake. Nature DOI: 10.1038/nature09358

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mabarker
1 / 5 (4) Aug 09, 2010
ID-ing genes associated wi Ca+ uptake is great, otherwise there is very little science in this article. *Primordial soup*??? Atheist M. Denton admitted there was no physical evidence for such a strange idea. Nowhere on Earth can 1 find any trace of p.s. that supposedly incubated *primal life* Zero evidence.
In fact, WAY back in August of 2010 Jack Szostak in New Scientist magazine (p. 26) asked us to use our imagination when describing *shallow ponds on the volcanic islands* How scientific is that?

*evolutionary serendipity*??? How quaint - how . . . religious.

Szostak then said in the New Scientist article, *The exact nature of that first cell . . . is still unknown.*
Ethelred
4 / 5 (4) Aug 09, 2010
*Primordial soup*??? Atheist M. Denton admitted there was no physical evidence for such a strange idea.
Which doesn't mean that it never existed. There is plenty of evidence that it could have existed.
Zero evidence.
Not a big surprise. Food gets eaten and that would result in the evidence getting eaten.

Now what about that lack of evidence for the Great Flood. There should lots. I should see it nearly everywhere and there isn't any. At all. NONE.
How scientific is that?
Very scientific. Imagine a man in a rocket with no windows. Then notice that Einstein did that and used the results to produce General Relativity.
*evolutionary serendipity*??? How quaint - how . . . religious.
How nonsensical to lie about it being religious.

The evidence to support YOU is nonexistent. Which is why you run off every time instead dealing with the questions. Like a good little Discovery Institute Running Puppy.

They want you to run because they know they are full of it.

Ethelred
kevinrtrs
1.2 / 5 (5) Aug 10, 2010
Now what about that lack of evidence for the Great Flood. There should lots. I should see it nearly everywhere and there isn't any. At all. NONE.

There is none so blind as those who would not see...

You do realize that since you have no documented proof of one cell inbibing another that your adherence to the theory is an act of faith? And hence religious? Because there was no-one there to witness that act and document it for posterity, you cannot make any absolute claim for it.

Similarly one is fully justified in saying that life appeared on earth in mature form without any intervening "evolutionary action". Why? Because no one was there to contradict such a statement and you can use all the fossil evidence to support such a case. So please tone down the responses and eat some humble pie.

Skeptic_Heretic
5 / 5 (3) Aug 10, 2010
You do realize that since you have no documented proof of one cell inbibing another that your adherence to the theory is an act of faith?
Everytime you eat meat you're allowing the imbibing of one cell by another. Are you retarded? Didn't you go to science class and watch the movie of an amoeba eating another prokaryote?
Similarly one is fully justified in saying that life appeared on earth in mature form without any intervening "evolutionary action". Why?
Because evolution doesn't have any bearing on the appearance of life, only on how life changes over time within a group of individuals and their subsequent generations.

We've been over this several times. You need evidence for a primordial soup? The ocean, look at it. It is still a soup of life and its subcomponents. You two, if you even are two seperate people, need to go crack a textbook, or perhaps get a proper education, or at least provide full quotation.
Skeptic_Heretic
5 / 5 (2) Aug 10, 2010
Just in case you'd like to read the full article by Szostak rather than the first few words and last two of the 3rd paragraph, here's the link.

http://http://www.newsci...gan.html

I even posted a youtube video that explained this in shiny bright colors for you two dumbasses. This isn't even new research, it's been around for over 10 years now.

Time to grow up and put the fantasy of your religion behind you.
Ethelred
5 / 5 (2) Aug 10, 2010
There is none so blind as those who would not see...
So how do you manage to get around with your eyes so tightly closed?
You do realize that since you have no documented proof of one cell inbibing another that your adherence to the theory is an act of faith?
Cells don't drink other cells. They EAT them.
Because there was no-one there to witness that act and document it for posterity, you cannot make any absolute claim for it.
I never claimed the article was right. Were you blind on that as well?

However it is not faith that the high explosive shell around the uranium in the Trinity device went off even though no one was looking at it. There was a really big BOOOMM which made it clear that the ignighters worked. What you are claiming is very far off claiming that I don't know the sun came up before my birth because I wasn't there. It is a ludicrous act of desperation in hopes that I won't notice that you won't answer my question about the Great Flood.

More thinking
Ethelred
5 / 5 (3) Aug 10, 2010
Similarly one is fully justified in saying that life appeared on earth in mature form without any intervening "evolutionary action"
No, there is no evidence to support that claim. There are single celled fossils. There are fossils of cells that are stuck together. There are fossils of early fish. There are fossils of early humans. In fact there are rather a lot of fossils and ALL of them are older than your idea of the Earth.
So please tone down the responses and eat some humble pie
Just because YOU don't know anything that doesn't mean that I don't. I do KNOW that the world is older than you and Ma think. The evidence is overwhelming. YOU are the one with the arrogant belief that you know more than scientists do. YOU are the one that insists that we have been on Earth for less time than the oldest cities have.

How about you tell us why we should believe without evidence? Why that isn't as arrogant as can be?

Why is it wrong for me ask questions?

Ethelred
otto1923
not rated yet Aug 11, 2010
*evolutionary serendipity*??? How quaint - how . . . religious.
Serendipity:
"1. The faculty of making fortunate discoveries by accident."

-In other words, luck. Is religion the deification of luck? Absolutely it is. *Things cant just 'happen', can they??!?*

Ma likes the word because she thinks it has something to do with 'serene' which evokes the vacuous look on the face of an enraptured godder. Or maybe she thinks Serenity Prayer, which isnt really religious at all.
There is none so blind as those who would not see...
'For he who has ears, let him hear!' For he who has brains, let him think!