A European team of researchers led by the European Molecular Biology Laboratory (EMBL) in Heidelberg (Germany) and Grenoble (France) found that the Brdt - a protein found only in sperm cells - plays a central role in controlling the re-uniting of sperm DNA. The results of the study, published in the journal Nature, shed light on the exceptionally hydrodynamic shape of the sperm.
In collaboration with colleagues of the Institut de Biologie Structural (IBS) - Jean Pierre Ebel Institute and Albert Bonniot (IAB) in France, EMBL researchers were able to determine a key to optimal code histone, revealing the mystery of the speed of spermatozoa. One thing is clear: the fertility depends largely on the speed of spermatozoa.
DNA (deoxyribonucleic acid) is contained in a complex structure called chromatin, which is the backbone of the chromosome. Long sequences of DNA are wrapped around proteins called histones. But what makes one sperm DNA? The researchers say that the sperm chromatin is more compact, reducing the size of the head of the sperm, thus making them more hydrodynamic.
Studies have shown that the control of chromatin is a very complicated mechanism. Histones are marked by a number of chemical markers, which encode the direct changes in chromatin structure. According to the researchers, "to bind different protein markers, through the combination of which can decrypt the code. "
Studies conducted in the past have shown that these proteins bind with one or more" fields "modular, each of which is marked by a single marker. Now scientists at EMBL, IBS IAB and discovered a further level of processing. Examining the link Brdt histone protein, the team found that it binds strongly to a histone with two special markers - acetyl groups (groups containing carbon and hydrogen) - using a single protein field.
" We were very surprised, "said Dr. EMBL Christoph Müller. We have analyzed the structure and found that the field formed a pocket, tying the two markers simultaneously." The
dr. Saadi Khochbin IAB said: "Over the sperm - just before the DNA is hyper - these markers are added throughout the chromatin, through a huge wave. Brdt If it is absent, there is the additional compaction, and the head sperm is less tapered. Brdt free male mice are infertile. "
However, scientists have said that one can only assume that the way in which the Brdt binds to histone markers has an important role in his ability to regroup.
"One hypothesis is that histone sequentially acquire markers and bunched only marking is completed," said Dr. Müller. "The Brdt binds to the last two markers in the sequence - making it the last step of the process - the final signal that initiates the hyper. IBS
Carlo Petosa said: "We are reviewing the structures of other proteins associated with chromatin and saw [that] this mechanism of markers is probably also used by them, increasing [therefore] our understanding of how it reads the histone code. "
Scientists believe that the results of their study will contribute to the solution of problems related to the development of sperm. The team is also evaluating the impact of this protein on male fertility. Posted by
cordis.europa.eu By
Kriagen
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