Sometimes research discovers more than expected. (It could be called serendipity.) In this case, researchers from the Max Planck Institute in Berlin (Germany) were exploring the bacterium Helicobacter pylori, which is a microscopic beasty that lives in the gut of about 50% of humanity. H. pylori, as it is abbreviated, has been linked to a number of major diseases – cancer, cardiovascular. So it’s a worthy target. Its genome was among the first to be sequenced, way back in 1997. Even then it was noticed that H. pylori didn’t seem to have enough genes to regulate its genetic transcription. Were some genes missing? What turned gene expression on and off?
These are the types of questions that beg for research, even for a field with more than its share of work to be done. The reason is that while exploring the peculiarities of H. pylori, it might also be possible to discover something more generally insightful. This, in fact, happened.
It had been suspected for a while that H. pylori had different kind(s) of gene regulator, in particular something called small RNA (sRNA). These are particles of RNA that have been shown to be much more common in all living things than previously thought. They are known to regulate genes by inhibiting protein production. However, it was believed that H. pylori had no sRNAs.
To determine if this was true or not, the researchers modified a computer technique called ‘deep sequencing’ (they altered its search and compare routines), and then ran through it the millions of RNA sequences produced in H. pylori cells. The result – yes, there were sRNAs in H. pylori. In fact, 60 of them were identified. This was comparable to the numbers found in other kinds of bacteria. So why was this not seen in H. pylori before? Because there is a protein missing that is necessary for gene regulation by sRNA.
What protein? How is it expressed? How does H. pylori use its sRNA – by some other method? More good questions to be researched.
There is a possibility of a new ‘expression pathway’ (jargon for the sequence of molecular changes that run from DNA (or RNA) to the building of proteins), which involves sRNAs in ways not previously known. Since sRNAs are almost ubiquitous in living cells, this is a possible new insight into (yet another) way of gene regulation. It’s remindful of the work now being done on ‘junk DNA’ where previously unsuspected sequences are actually involved in gene regulation. It’s known that how genes become used in so many different ways within living cells requires a vast network of chemical relationships (pathways in particular), but there is so much yet to be learned. This is the kind of study that asks the right questions, gets some appropriately nifty tools (in this case computer programs), and gets to look into perhaps a whole new field of study.
A breakthrough in decoding gene regulation of Helicobacter pylori has been made by an international research team led by Jörg Vogel of the Max Planck Institute for Infection Biology in Berlin. Using a newly developed sequencing technique, the re-searchers discovered 60 small ribonucleic acids (sRNAs) – tiny RNA-particles which can regulate genes – in the genome of this human pathogen. These findings could facilitate the development of new therapeutic strategies against this wide-spread pathogen. (Nature, February 17th 2010)
[Source: Max Planck Institute, Berlin]