Citations 2
Germline mutations in a G protein identify signaling cross-talk in T cells
Ham, Hyoungjun , Jing, Huie , Lamborn, Ian T. , Kober, M. , Anderson, David E. , Druey, Kirk M. , Mandl, Judith N. , Isidor, Bertrand , Freeman, Alexandra F. , Ganesan, Sundar , Karsak, Meliha , Mustillo, Peter , Teo, Juliana , Zolkipli‐Cunningham, Zarazuela , Lecoquierre, François , Schmid, Jana Pachlopnik , Kuhns, Douglas B. , Xu, Xuehua , Al–Herz, Waleed , Terhal, Paulien A., Muurinen, Mari , Barlogis, Vincent , Danielson, Jeffrey J. , Stewart, Helen , Rading, Sebastian, Keren, Boris , Pfundt, Rolph , Potocki, Lorraine , Olivier, Kenneth N., Faivre, Laurence , Wong, Melanie , Puel, Anne , Chou, Janet , Tusseau, Maud, Moutsopoulos, Niki M. , Matthews, Helen, Simons, Cas , Fink, Danielle , Kong, Heidi H. , Kabát, Juraj , Kim, Woo Sung , Bierhals, Tatjana , Meguro, Kazuyuki , Gu, Jingwen , Stoddard, Jennifer , Banos-Pinero, Benito, Slack, Maria A., Trivellin, Giampaolo , Mazel, Benoît , Li, Samuel T. , Watts, Val J. , Rodriguez-Quevedo, Maria F. , Bruel, Ange‐Line , Lehalle, Daphné , Torres, Daniel , Sullivan, Kathleen E. , Duffourd, Yannis, Similuk, Morgan , Blanc, Pierre , Jin, Tian, Geha, Raif S., Casanova, Jean‐Laurent , Mäkitie, Outi , Edery, Patrick , Germain, Ronald N. , Billadeau, Daniel D. , Zhang, Yu , Lenardo, Michael J. , Kober, Megan M , Koval, Alexey , Anderson, D Eric , Druey, Kirk M , Mandl, Judith N , Isidor, Bertrand , Ferreira, Carlos R , Freeman, Alexandra F , Karsak, Meliha , Mustillo, Peter J , Teo, Juliana , Chatron, Nicolas , Lecoquierre, Francois , Oler, Andrew J , Schmid, Jana Pachlopnik , Kuhns, Douglas B , Xu, Xuehua , Hauck, Fabian , Al-Herz, Waleed , Wagner, Matias , Terhal, Paulien A , Muurinen, Mari , Barlogis, Vincent , Loid, Petra , Keren, Boris , Pfundt, Rolph , Zarember, Kol A , Vill, Katharina , Olivier, Kenneth N , Lesca, Gaetan , Faivre, Laurence , Puel, Anne , Chou, Janet , Moutsopoulos, Niki M , Simons, Cas , Soldatos, Ariane , Masle-Farquhar, Etienne , Pittaluga, Stefania , Brink, Robert , Kong, Heidi H , Kabat, Juraj , Bierhals, Tatjana , Hsu, Amy P. , Gu, Jingwen , Trivellin, Giampaolo , Mazel, Benoît , Soomann, Maarja , Li, Samuel , Watts, Val J , Stratakis, Constantine A , Rodriguez-Quevedo, Maria F , Bruel, Ange-Line , Lipsanen-Nyman, Marita , Saultier, Paul , Lehalle, Daphne , Torres, Daniel , Barbarot, Sébastien , Neu, Axel , Similuk, Morgan N , McWalter, Kirsty , Blanc, Pierre , Bézieau, Stéphane , Geha, Raif S , Casanova, Jean Laurent , Makitie, Outi M , Edery, Patrick , Christodoulou, John , Germain, Ronald N , Goodnow, Christopher C , Sakmar, Thomas P , Billadeau, Daniel D , Kury, Sebastien , Katanaev, Vladimir L , Zhang, Yu , Lenardo, Michael J , Su, Helen C , Berchiche, Yamina A. , Wagner, Matias , Cruz, Phillip , Lesca, Gaëtan , Tusseau, Maud , Taft, Ryan J. , Pittaluga, Stefania , Baños-Piñero, Benito, Stratakis, Constantine A. , Jain, Rashmi, Bezieau, Stéphane , Jin, Tian , Kubisch, Christian , Küry, Sébastien , Su, Helen C.
Science | September 19, 2024 | Volume: 385 | Issue: 6715 | Pages: No page available
Humans with monogenic inborn errors responsible for extreme disease phenotypes can reveal essential physiological pathways. We investigated germline mutations in GNAI2 , which encodes G αi2 , a key component in heterotrimeric G protein signal transduction usually thought to regulate adenylyl cyclase–mediated cyclic adenosine monophosphate (cAMP) production. Patients with activating G αi2 mutations had clinical presentations that included impaired immunity. Mutant G αi2 impaired cell migration and augmented responses to T cell receptor (TCR) stimulation. We found that mutant G αi2 influenced TCR signaling by sequestering the guanosine triphosphatase (GTPase)–activating protein RASA2, thereby promoting RAS activation and increasing downstream extracellular signal–regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)–AKT S6 signaling to drive cellular growth and proliferation.
Human PIK3R1 mutations disrupt lymphocyte differentiation to cause activated PI3Kδ syndrome 2
Nguyen, Tina , Lau, Anthony , Bier, Julia , Cooke, Kristen C. , Lenthall, Helen , Ruiz‐Diaz, Stephanie , Avery, Danielle T. , Brigden, Henry , Zahra, David , Sewell, William A. , Droney, Luke , Okada, Satoshi , Asano, Takaki , Abolhassani, Hassan , Chavoshzadeh, Zahra , Abraham, Roshini S. , Rajapakse, Nipunie , Klee, Eric W. , Church, Joseph A., Williams, Andrew , Wong, Melanie , Burkhart, Christoph , Uzel, Gülbû , James, David E. , Deenick, Elissa K. , Croucher, David R , James, David E , Ma, Cindy S , Brink, Robert , Tangye, Stuart G , Deenick, Elissa K , Zahra, David
Journal of Experimental Medicine | February 28, 2023 | Volume: 220 | Issue: 6 | Pages: No page available
Heterozygous loss-of-function (LOF) mutations in PIK3R1 (encoding phosphatidylinositol 3-kinase [PI3K] regulatory subunits) cause activated PI3Kδ syndrome 2 (APDS2), which has a similar clinical profile to APDS1, caused by heterozygous gain-of-function (GOF) mutations in PIK3CD (encoding the PI3K p110δ catalytic subunit). While several studies have established how PIK3CD GOF leads to immune dysregulation, less is known about how PIK3R1 LOF mutations alter cellular function. By studying a novel CRISPR/Cas9 mouse model and patients’ immune cells, we determined how PIK3R1 LOF alters cellular function. We observed some overlap in cellular defects in APDS1 and APDS2, including decreased intrinsic B cell class switching and defective Tfh cell function. However, we also identified unique APDS2 phenotypes including defective expansion and affinity maturation of Pik3r1 LOF B cells following immunization, and decreased survival of Pik3r1 LOF pups. Further, we observed clear differences in the way Pik3r1 LOF and Pik3cd GOF altered signaling. Together these results demonstrate crucial differences between these two genetic etiologies.