SCYL pseudokinases in neuronal function and survival

The generation of mice lacking SCYL1 or SCYL2 and the identification of Scyl1 as the causative gene in the motor neuron disease mouse model muscle deficient（Scyl1^（mdf/mdf）） demonstrated the importance of the SCY1-like family of protein pseudokinases in neuronal function and survival.Several essential cellular processes such as intracellular trafficking and nuclear tRNA export are thought to be regulated by SCYL proteins.However,whether deregulation of these processes contributes to the neurodegenerative processes associated with the loss of SCYL proteins is still unclear.Here,I briefly review the evidence supporting that SCYL proteins play a role in these processes and discuss their possible involvement in the neuronal functions of SCYL proteins.I also propose ways to determine the importance of these pathways for the functions of SCYL proteins in vivo.

PD-L1 expression is regulated by ATP-binding of the ERBB3 pseudokinase domain

How PD-L1 expression is regulated in cancer is poorly understood.Here,we report that the ATP-binding activity of ERBB3 pseudokinase regulates PD-L1 gene expression in colorectal cancers(CRCs).ERBB3 is one of the four members of the EGF receptor family,all with protein tyrosine kinase domains.ERBB3 is a pseudokinase with a high binding affin-ity to ATP.We showed that ERBB3 ATP-binding inactivation mutant reduces tumorigenicity in genetically engineered mouse models and impairs xenograft tumor growth of CRC cell lines.The ERBB3 ATP-binding mutant cells dramatically reduce IFN-g-induced PD-L1 expres-sion.Mechanistically,ERBB3 regulates IFN-g-induced PD-L1 expression through the IRS1-PI3K-PDK1-RSK-CREB signaling axis.CREB is the transcription factor that regulates PD-L1 gene expression in CRC cells.Knockin of a tumor-derived ERBB3 mutation located in the ki-nase domain sensitizes mouse colon cancers to anti-PD1 antibody therapy,suggesting that ERBB3 mutations could be predictive biomarkers for tumors amenable to immune check-point therapy.

Highlights of the 2nd International Symposium on Tribbles and Diseases: tribbles tremble in therapeutics for immunity, metabolism, fundamental cell biology and cancer

The Tribbles(TRIB) family of pseudokinase proteins has been shown to play key roles in cell cycle, metabolic diseases, chronic inflammatory disease, and cancer development. A better understanding of the mechanisms of TRIB pseudokinases could provide new insights for disease development and help promote TRIB proteins as novel therapeutic targets for drug discovery. At the 2 nd International Symposium on Tribbles and Diseases held on May 7–9, 2018 in Beijing, China, a group of leading Tribbles scientists reported their findings and ongoing studies about the effects of the different TRIB proteins in the areas of immunity, metabolism, fundamental cell biology and cancer. Here, we summarize important and insightful overviews from 4 keynote lectures, 13 plenary lectures and 8 short talks that took place during this meeting. These findings may offer new insights for the understanding of the roles of TRIB pseudokinases in the development of various diseases.