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.
Properties of the Arg376 residue of the proton-coupled folate transporter (PCFT-SLC46A1) and a glutamine mutant causing hereditary folate malabsorption
Mahadeo, Kris M. , Diop-Bove, Ndeye, Shin, Daniel Sanghoon , Unal, Ersin Selcuk, Teo, Juliana , Zhao, Rongbao, Chang, Min‐Hwang , Fulterer, Andreas, Romero, Michael F. , Goldman, I. David, Romero, Michael F
American Journal of Physiology-Cell Physiology | August 5, 2010 | Volume: 299 | Issue: 5 | Pages: C1153-C1161
The proton-coupled folate transporter (PCFT-SLC46A1) is required for intestinal folate absorption and is mutated in the autosomal recessive disorder, hereditary folate malabsorption (HFM). This report characterizes properties and requirements of the R376 residue in PCFT function, including a R376Q mutant associated with HFM. Gln, Cys, and Ala substitutions resulted in markedly impaired transport of 5-formyltetrahydrofolate (5-FTHF) and 5-methyltetrahydrofolate (5-MTHF) due to an increase in Km and decrease in Vmax in HeLa R1–11 transfectants lacking endogenous folate transport function. In contrast, although the influx Km for pemetrexed was increased, transport was fully preserved at saturating concentrations and enhanced for the like-charged R376K- and R376H-PCFT. Pemetrexed and 5-FTHF influx mediated by R376Q-PCFT was markedly decreased at pH 5.5 compared with wild-type PCFT. However, while pemetrexed transport was substantially preserved at low pH (4.5–5.0), 5-FTHF transport remained very low. Electrophysiological studies in Xenopus oocytes demonstrated that 1) the R376Q mutant, like wild-type PCFT, transports protons in the absence of folate substrate, and in this respect has channel-like properties; and 2) the influx Km mediated by R376Q-PCFT is increased for 5-MTHF, 5-FTHF, and pemetrexed. The data suggest that mutation of the R376 residue to Gln impairs proton binding which, in turn, modulates the folate-binding pocket and depresses the rate of conformational alteration of the carrier, a change that appears to be, in part, substrate dependent.