UNIGE scientists develop a novel device to visualise palmitoylation course of in residing cells

Peripheral membrane proteins have the particularity of quickly binding to cell membranes, a vital step for them to have the ability to fulfil their organic operate. To do that, sure enzymes that catalyze their lipid modification come into motion. This course of is named”palmitoylation”. A few of these proteins can mutate and turn out to be oncogenic, such because the RAS proteins, that are accountable for about one-third of cancers.

So as to perceive how palmitoylation works and to make use of it for therapeutic functions, scientists from the College of Geneva (UNIGE), Switzerland, developed a novel device to visualise this course of in residing cells. They’ve proven that, opposite to what was thought, palmitoylation is feasible not solely within the Golgi equipment, the same old web site for protein processing and supply, but in addition on the very web site the place the protein should act, e.g. the plasma membrane. This discovery, to be learn within the journal Nature Communications, paves the way in which to modern drug discovery methods to focus on very exactly the membrane binding – and subsequently exercise – of oncogenic proteins.

Palmitoylation consist within the introduction of fatty acids into sure proteins for them to have the ability to bind to cell membranes. This mechanism is ruled by exact guidelines, which depend upon the sequence of every sort of protein, and on the presence of specialised enzymes. Till now, the scientific group believed that palmitoylation of peripheral membrane proteins may solely happen in a single place within the cell, the Golgi equipment.

Certainly, these proteins are produced within the cytosol – the cell fluid – after which ‘swim’ to the Golgi equipment, the place they’re modified earlier than being transported to the place they should act. However, we hypothesized the opportunity of native palmitoylation, with out passing via the Golgi equipment. If that is true, it opens up fully new prospects for the intervention of this mechanism.”

Gonzalo Solis, researcher, Division of Cell Physiology and Metabolism, UNIGE’s School of Drugs, and lead writer

Observing and manipulating proteins

To check this speculation, the analysis workforce led by Vladimir Katanaev, professor within the Division of Cell Physiology and Metabolism and on the Centre for Translational Analysis in Onco-Haematology on the UNIGE School of Drugs, centered on a protein referred to as Gαo, which is often positioned on the plasma membrane and the Golgi equipment.

The methodology used is totally new: “We introduced the palmitoylating enzymes to a completely completely different compartment within the cell, the nuclear membrane,” explains Gonzalo Solis. “Gαo was recruited on the nuclear membrane, permitting us to determine the particular enzyme that palmitoylates them. We thus confirmed that this course of can happen on the very web site the protein is required.”

Opposite to common biochemical methodologies, the device developed by Vladimir Katanaev and his workforce, which they named SwissKASH, can also be the primary to maintain the cell alive and permits for the remark of the method dynamically. “Till now, there was no various to destroying the cell,” says Vladimir Katanaev. “Our technique additionally makes it doable to find out precisely which protein reacts to which enzyme regionally, which is crucial if we wish to management this mechanism for therapeutic functions.”

A brand new drug goal

A number of peripheral membrane proteins, and particularly Gα subunit proteins and RAS proteins, are inclined to mutation and thus purchase an aggressive oncogenic potential. Their oncogenicity relies on their potential to bind to the plasma membrane; palmitoylation thus performs a key position within the transformation of a wholesome cell right into a cancerous one.

“Inhibiting the enzyme that induces palmitoylation, and stopping the oncogenic protein from binding to the plasma membrane, may subsequently defuse its pathogenicity,” factors out Gonzalo Solis. “We are able to thus think about blocking this particular response with out unbalancing the entire system.” The scientists will now intention at automatizing this technique to check the impact of an entire collection of pharmaceutical merchandise on the palmitoylation of chosen oncoproteins, in addition to testing their toxicity on the entire cell.

Journal reference:

Solis, G.P., et al. (2022) Native and substrate-specific S-palmitoylation determines subcellular localization of Gαo. Nature Communications. doi.org/10.1038/s41467-022-29685-8.



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