Functional Characterization Of 26S Proteasome Myristoylation In Mammals

Protein is the material basis of all life,and its synthesis and degradation are strictly and precisely regulated.The ubiquitin-proteasome system mediates the degradation of more than 80%of proteins in eukaryotic cells.The 26S proteasome is essential for maintaining normal physiological processes,but the research on the regulation mechanism of the proteasome is still very limited.We found that N-myristoylation of the proteasome subunit Rpt2 can mediate the membrane localization of the proteasome.Here I focus on the functional study of membrane-localized proteasome in mammals.We generated the Rpt2-G2A heterozygous knock-in mice in the CNS and the systemic Rpt2-G2A knock-in mice.The heterozygous knock-in of Rpt2-G2A in the CNS caused mice to appear more anxious under certain conditions.Systemic Rpt2-G2A homozygous knock-in mice showed embryonic death and abnormal development of liver and other organs.We used RNA-seq and SILAC-MS to study the role of Rpt2 N-myristoylation in regulating cell function.The results showed that Rpt2 N-myristoylation mainly regulates specific membrane-related proteins,including important components in a variety of signaling pathways.Anomaly in these development and disease related pathways may be the main cause of embryonic death in G2A/G2A mice.Therefore,the Rpt2 N-myristoylation plays an important role in mammalian cells.This work established for the first time a mouse model to study the in vivo function of the membrane-bound proteasomes.It has also deepened our understanding of proteasome regulation and provided important evidence for the concept of compartmentalized proteasomal degradation.