Discovery of New Components For Protein Transport
A new enzyme has been found by scientists from Ruhr University in Bochum, this enzyme provides new insight into the importation of specified cell based organelles commonly referred to as peroxisomes. The findings from this research were published in the Journal of Biological Chemistry. The research team that discovered these findings was headed by professor Erdmann of the Department of Systematic Biochemistry. The professor says that the enzyme UBp15p works in unison with two additional enzymes in order to enable the conversion of the protein transportation mechanism back to its original state after work has been done.
The enzyme release a very specific sequence of signals from a protein which has great significance for the recycling and transport of this protein, this enables the commencement of a new protein sequence. Professor Erdman went on to say that using Ubp15p, scientists could discover uncover the answers to many unknown mysteries relating to the transportation of proteins into peroxisomes.
Peroxisomes are biological 'devices' with a large number of functions, a good way in which peroxisomes illustrate this fact is the way in which they play a role in the catalysis of fatty acids and harmful hydrogen peroxide. If these organelles were to suffer some form of malfunction, as happens with disorders such as zellweger syndrome, then this would lead to adverse effects on the kidneys, liver, and the brain itself. To ensure the correct functioning of peroxisomes, they require precise proteins, but peroxisomes are not able to make these proteins. Therefore, a shuttle mechanism made up of a number of receptors has to bring in the proteins needed from the cytosol. The receptors are able to correctly identify the precise proteins that are required by the peroxisomes inside the cytosol and thus lead them to their intended location. Once there, the proteins would bind with the cell membrane of the peroxisome and become a part of the 'pathway' that would allow for the transportation of proteins into the inside. The receptors have an export signal known as ubiquitin, on their individual receptor cells, these make sure that they are released from within the peroxisome cell membrane and made available for further transportation. The state of the ubiquitin signal following these events is currently unknown.
The discovery of new export components was made by professor Erdmann's team and was published in the journal Nature Cell Biology. Two motor components were described by Erdmann's team, this had the ability to remove the ubiquitin marked receptor Pex5p from the cell membrane and facilitate for its transportation back inside the cytosol.
Other scientific research teams were able to find Ubp15p within living yeast cells and thus they proved that the enzyme does come into contact with some motor proteins n order for them to reach the peroxisomes.