Scientists discover enzyme crucial to the transportation of proteins within cells

Scientists at the University of British Columbia have discovered an enzyme in mammals crucial to the transportation of proteins within cells. Published today in Neuron, this discovery opens new avenues of understanding of the mechanisms underlying neuronal function and new therapeutic approaches for neurodegenerative diseases such as Alzheimers and Huntington Disease.

The enzyme, HIP14, is a palmitoyl transferase that adds signaling molecules to proteins resulting in their transportation to specific cellular locations where they perform essential functions. This process known as palmitoylation is extremely important for the normal functioning of the nervous system where proteins are transported rapidly within nerve cells known as neurons.

Until now, scientists did not know how mammalian proteins become palmitoylated. During their study of Huntington Disease, Dr. Michael Hayden’s team at the Centre for Molecular Medicine and Therapeutics had previously identified a protein called HIP14 and recognized that it might play a role in palmitoylation. To further understand this mechanism, the Hayden team formed a partnership with Dr. Alaa El-Husseini and his team at the Brain Research Centre who are experts in the field of protein palmitoylation. Through this unique collaboration between experts in complementary fields, they discovered that HIP14 is indeed a mammalian palmitoyl transferase.

The teams also discovered that in the absence of the HIP14 enzyme, proteins were not transported to locations in the cell where they are needed. This change in protein trafficking is thought to result in severe neuronal dysfunction and may be a mechanism underlying diseases such as Alzheimers and Huntington Disease.

This research was funded by the Michael Smith Foundation for Health Research, the Canadian Institute of Health Research and the High Q Foundation.