TY - JOUR
T1 - A short binding site in the KPC1 ubiquitin ligase mediates processing of NF-κB1 p105 to p50
T2 - A potential for a tumor-suppressive PROTAC
AU - Goldhirsh, Gilad
AU - Kravtsova-Ivantsiv, Yelena
AU - Satish, Gandhesiri
AU - Ziv, Tamar
AU - Brik, Ashraf
AU - Ciechanover, Aaron
N1 - Funding Information: The authors thank Jered R. Wells, PhD, Yakun Zhang, MS, and Ehsan Samei, PhD, of the Duke University Clinical Imaging Physics Group for allowing the American College of Radiology to use their code to automatically determine patient size from localizer images in the American College of Radiology Dose Index Registry.
PY - 2021/12/7
Y1 - 2021/12/7
N2 - Nuclear factor κB (NF-κB) is an important transcriptional regulator that is involved in numerous cellular processes, including cell proliferation, immune response, cell survival, and malignant transformation. It relies on the ubiquitin–proteasome system (UPS) for several of the steps in the concerted cascade of its activation. Previously, we showed that the ubiquitin (Ub) ligase KPC1 is involved in ubiquitination and limited proteasomal processing of the NF-κB1 p105 precursor to generate the p50 active subunit of the “canonical” heterodimeric transcription factor p50–p65. Overexpression of KPC1 with the generation of an excessive amount of p50 was shown to suppress tumors, an effect which is due to multiple mechanisms. Among them are suppression of expression of programmed cell death-ligand 1 (PD-L1), overexpression of a broad array of tumor suppressors, and secretion of cytokines which results in recruitment of suppressive immune cells into the tumor. Here, we show that the site of KPC1 to which p105 binds is exceptionally short and is made up of the seven amino acids WILVRLW. Attachment of this short stretch to a small residual part (∼20%) of the ligase that also contains the essential Really Interesting New Gene (RING)-finger domain was sufficient to bind p105, conjugate to it Ub, and suppress tumor growth in an animal model. Fusion of the seven amino acids to a Von Hippel–Lindau protein (pVHL)-binding ligand (which serves as a “universal” ligase for many proteolysis-targeting chimeras; PROTACs) resulted in a compound that stimulated conjugation of Ub to p105 in a cell-free system and its processing to p50 in cells and restricted cell growth.
AB - Nuclear factor κB (NF-κB) is an important transcriptional regulator that is involved in numerous cellular processes, including cell proliferation, immune response, cell survival, and malignant transformation. It relies on the ubiquitin–proteasome system (UPS) for several of the steps in the concerted cascade of its activation. Previously, we showed that the ubiquitin (Ub) ligase KPC1 is involved in ubiquitination and limited proteasomal processing of the NF-κB1 p105 precursor to generate the p50 active subunit of the “canonical” heterodimeric transcription factor p50–p65. Overexpression of KPC1 with the generation of an excessive amount of p50 was shown to suppress tumors, an effect which is due to multiple mechanisms. Among them are suppression of expression of programmed cell death-ligand 1 (PD-L1), overexpression of a broad array of tumor suppressors, and secretion of cytokines which results in recruitment of suppressive immune cells into the tumor. Here, we show that the site of KPC1 to which p105 binds is exceptionally short and is made up of the seven amino acids WILVRLW. Attachment of this short stretch to a small residual part (∼20%) of the ligase that also contains the essential Really Interesting New Gene (RING)-finger domain was sufficient to bind p105, conjugate to it Ub, and suppress tumor growth in an animal model. Fusion of the seven amino acids to a Von Hippel–Lindau protein (pVHL)-binding ligand (which serves as a “universal” ligase for many proteolysis-targeting chimeras; PROTACs) resulted in a compound that stimulated conjugation of Ub to p105 in a cell-free system and its processing to p50 in cells and restricted cell growth.
KW - KPC1
KW - NF-κB
KW - PROTAC
KW - p50
KW - ubiquitin–proteasome
UR - http://www.scopus.com/inward/record.url?scp=85122451466&partnerID=8YFLogxK
U2 - https://doi.org/10.1073/pnas.2117254118
DO - https://doi.org/10.1073/pnas.2117254118
M3 - مقالة
C2 - 34873064
SN - 0027-8424
VL - 118
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 49
M1 - e2117254118
ER -