Grigory Ryzhakov – Russian Writer

Brain. Memory. Chromatin. DNA. RbAp48

PLoSBiol4.e126.Fig6fNeuron

Colourful section of a brain. Someone was definitely bright 🙂 (By Wei-Chung Allen Lee, Hayden Huang, Guoping Feng, Joshua R. Sanes, Emery N. Brown, Peter T. So, Elly Nedivi [CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons)

A curious study has just been published describing research on cellular proteins involved in sustaining brain memory. It was an examination of post mortem brains from deceased individuals aged 33-88, focusing on changes in gene expression in connection with senescence and age-related memory loss. The study found the expression of a gene encoding the RbAp48 protein declined in old brains. The scientists injected a virus expressing this gene into brains of old mice and found an improved performance of these mice in cognitive tests.

Hippocampus

Hippocampus is the area of our brain where RbAp48 is believed to play role in sustaining memory (via Wikimedia commons)

 

This implies that RbAp48 is involved in sustaining our memory and that our age-related forgetfulness could be partially caused by decreasing amounts of this protein in our brain cells.

Coincidentally, a relative of human RbAp48 in the plant called Arabidopsis is important for imprinting, which a type of genomic memory.

Exciting, so potentially we could design therapies preventing age-related memory loss.

But that’s not the end of the story. What does actually this RbAp48 protein do in our cells? It works in the nuclei of cells and helps to re-model chromatin by binding to histones 3 and 4, proteins that coat genomic DNA in every animal cell that has a nucleus.

Our genome is packed into orderly structures called nucleosomes and this packing controls the process of gene expression, whether a messenger RNA or mRNA (a molecule that is used as an intermediate to synthesize a protein from a gene it is encoded in) will be synthesized on a particular gene or not, when it’s going to be done and what amount of mRNA is getting produced – ‘Hey, easy you!’ I hear you exclaiming. He he, sorry, I got carried away.

In lay terms this above-mentioned abracadabra means that our memory depends on a chromatin protein that controls expression of genes in brain cells. From DNA to memory.

I already see too much excitement online about RbAp48. I must say that as it is such a fundamentally important protein, it deals with more things than just memory. For instance, there are reports on its role  in cancer cells.

Another study shows that  in planarian worms it drives differentiation of stem cells and aids regeneration. So, if you cut the worm and suppress this production of RbAp48, the animal won’t restore its tail very easily as you can see on the picture below.

F1.large

Regeneration of tails in planarian worms in the presence (control) or absence (RNAi) of RbAp48, 4 or 14d after cutting (Bonuccelli et al., 2010 J Cell Science)

 

So, you see before we mess around with these protein using drugs, we need to understand what else RbAp48 does, to avoid possible side effects. Everything is connected in our cells. RbAp48 helps to re-model our genome and it’s no surprise this is needed for sustaining the long-term memory.

Now the interesting thing is what is the link between RbAp48 and our memory, what kind of genes regulated by RbAp48 actually contribute to our memory. Some of them might be involved in synaptic plasticity of neurons?

Thinking about this one realises how much we still don’t know about our brain, about our cells and how processes in our cells are connected to global physiological phenomena  such as memory.

More info on the subject. And yes, a little celebratory dance – this is my 100th blog post 🙂

 

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