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Specific protein complex associated with Parkinson-like symptoms

Inactivation of specific protein complex that play a key role in keeping genes turned off results in nerve cells not producing enough of the essential neurotransmitter. This may be part of the explanation for conditions like Parkinson's and anxiety disorders. This is the finding of researchers at Umeå University, Lund University and Karolinska Institutet in Sweden.

"We've seen that if this protein complex is inactive, the ability to turn off genes that control other functions is impaired. This in turn turns off genes needed to maintain nerve cell function. In animal studies, we can See John Holmberg, a professor at the Department of Molecular Biology at Umeå University and one of the lead authors of the study:

After neurons are formed during fetal development, they typically maintain their identity and function for the rest of their lives. In addition to the genetic programs needed to form and keep nerve cells active, genes that control other properties also need to be permanently "silenced." The current study shows that silencing of this unrelated gene depends on a specific protein complex, PRC2.

 

Without a functioning PRC2 complex, mature neurons that produce the important neurotransmitters dopamine and serotonin gradually lose their identity and function. In Parkinson's disease, dopamine-producing cells die, and serotonin deficiency has been linked to mental health problems. When testing the mice, the researchers observed gradual changes in the mice's behavior, such as motor symptoms typical of Parkinson's disease.

The LH2 used in this study is a pigment-protein complex in the purple photosynthetic bacterium Rhododendron acidophilus strain 10050 43, 44, 45, 46. It contains 27 species of bacteriochlorophyll a (BChl) that form two circular BChl aggregates of different radii. The inner and outer rings consist of 18 and 9 BChls, respectively, which were named B850 and B800 due to their absorption wavelength of 47. The formation of such BChl aggregates results in efficient light collection48,49,50. The light energy absorbed by B800 is transferred to B850 with a time constant of approximately 700 fs51. The collected excitation energy is further transferred to the core antenna-reaction center complex (LH1-RC) and used in photosynthetic reactions43,52,53. Yoneda et al. The enhancement of light absorption efficiency by the conjugation of A647 with LH2 was successfully demonstrated, which was attributed to the effective EET from A647 to BChl 40. They then speculated on the possible location of A647 in LH2-A647 based on the Förster equations 40, 41, 42 using the measured data of the FRET rate constant. Although they have made great achievements in artificially modifying protein function, the prediction of the location of A647 It remains to be reviewed because as mentioned before, they use a direction factor of 2/3 for intermolecular distance calculations. While LH2-A647 shows no signal for A647 in the linear dichroic spectrum, indicating average orientation, A647 covalently binds to LH2 through a linker in a crowded environment, which may limit molecular orientation. Accurate prediction of the position of A647 in LH2 is expected to further improve FRET efficiency by modifying the linker

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