Rce1: mechanism and inhibition

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Signaling

Background:

• Ras converting enzyme 1 (Rce1) is an endoplasmic reticulum-localized endoprotease.
• It processes CaaX proteins, vital for cell signaling pathways like Ras, heterotrimeric GTPases, and nuclear lamins.
• Dysregulation of CaaX proteins, particularly Ras, is linked to cancer development.

Purpose of the Study:

• To elucidate the proteolytic mechanism of Rce1.
• To identify substrate specificity and recognition determinants for Rce1.
• To explore the potential of Rce1 as a therapeutic target for cancer and other diseases.

Main Methods:

• Sequence alignment, mutational studies, and analysis of crystallographic data to propose a novel catalytic mechanism.
• In vivo and in vitro reporter assays to study Rce1 activity and substrate specificity.
• Evaluation of substrate mimetics and 8-hydroxyquinoline derivatives as potential inhibitors.

Main Results:

• Rce1 employs a novel mechanism involving glutamate-activated water and an oxyanion hole.
• The enzyme exclusively cleaves prenylated substrates, with the a2 residue (Ile, Leu, or Val) being critical for recognition.
• 8-hydroxyquinoline derivatives showed potential in mislocalizing mammalian Ras isoforms.

Conclusions:

• Understanding Rce1's mechanism and substrate specificity provides insight into CaaX protein regulation.
• The development of potent and selective Rce1 inhibitors is a promising therapeutic strategy for cancer and other diseases.
• Further research is needed on cleavage specificity, chemical inhibition, and Rce1's broader therapeutic potential.