Revealing the circuits driving protein gradients
Key cellular processes, such as cell differentiation, rely on protein gradients, i.e. the uneven distribution of proteins within specific locations in the cell. The mechanisms responsible for these gradients are difficult to disentangle due to their high spatial and temporal resolution and the fact that they are often regulated by feedback circuitries.
Combining physics and biology…
To unravel the complexity of protein gradients, Dr. Sofia Barbieri, an independent researcher hosted in the laboratory of Prof. Monica Gotta, has developed an innovative interdisciplinary approach that combines biology and the principles of physics. This unique methodology has already shed light on the biophysical mechanisms regulating the formation of the gradient of PLK-1, a key regulator of cell division and cell polarity.
… allowed to decipher the complex circuitries behind patterning formation in C. elegans embryos
In their latest study published in the journal Proceedings of the National Academy of Sciences USA, Dr. Barbieri and colleagues identified . While it was previously shown that both MEX-6 and the essential and highly similar protein MEX-5 are responsible for the formation of the PLK-1 gradient, their experiments now revealed that PLK-1 also influences MEX-5 and MEX-6 gradients through two distinct circuits (yellow arrows in the figure below). PLK-1 shapes the MEX-5 gradient indirectly by regulating additional proteins at the cell cortex (light blue in the figure), while it modulates the gradient of MEX-6 by directly interacting with MEX-6.
MEX-5 and MEX-6 (black arrows) both influence the gradient of PLK-1 in the C. elegans one-cell embryo, but PLK-1 also affects MEX-5 and MEX-6 gradients (yellow arrows). © Sofia Barbieri