Daily Archives: April 15, 2009

Taking on a second job

Recent research has identified a protein that is essential for mitochondrial function:

Cellular respiration depends on proteins synthesised outside the mitochondrion and imported into it, and on proteins synthesised inside the mitochondrion from its own DNA. Researchers at Karolinska Institutet have now shown that a specific gene (Tfb1m) in the cell’s nucleus codes for a protein (TFB1M) that is essential to mitochondrial protein synthesis. If TFB1M is missing, mitochondria are unable to produce any proteins at all and cellular respiration cannot take place.

Sounds like a crucial protein. So what is TFB1M?

The transcription of genes from mitochondrial DNA requires a mitochondrial RNA polymerase (see POLRMT, MIM 601778) and a DNA-binding transcription factor (see TFAM, MIM 600438). Transcription factor B1 (TFB1M) is a part of this transcription complex.[supplied by OMIM][1]

So it’s an important transcription factor needed to express all the mitochondrial genes.

Is it a recent innovation or does it extend far back into deep time?
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Eukaryotic Phylogeny

I got this from a paper by Nicole King (I can’t find it at the moment and will put up the reference once I find it):


First, it will be handy to refer back to this when exploring the ancient, eukaryotic tool kit some more.

Second, it you strain your eyes to read the legend, you’ll notice that multicellularity has emerged several times, independently.