TY - JOUR
T1 - Interplay between HGAL and Grb2 proteins regulates B-cell receptor signaling
AU - Jiang, Xiaoyu
AU - Lu, Xiaoqing
AU - Zhang, Yu
AU - Lacaria, Leda
AU - Schuchardt, Brett J.
AU - Mikles, David C.
AU - Magistri, Marco
AU - García-Ramírez, Idoia
AU - Sanchez-Garcia, Isidro
AU - Farooq, Amjad
AU - Verdun, Ramiro E.
AU - Abdulreda, Midhat H.
AU - Moy, Vincent T.
AU - Lossos, Izidore S.
N1 - Funding Information:
X.J. is supported by the Stanley J. Glaser Foundation (research award UM SJG 2017-8), the American Cancer Society (institutional research grant 98-277-13), and the University of Miami Sylvester Comprehensive Cancer Center. A.F. is supported by the National Institutes of Health, National Institute of General Medical Sciences (grant R01-GM083897) and the Sylvester Comprehensive Cancer Center. V.T.M. is supported by a BioNIUM Pilot Project Award. I.S.L. is supported by the American Society of Hematology (bridge grant), the National Institutes of Health, National Cancer Institute (grant R01CA233945), the Dwoskin Family Foundation, the Recio Family Foundation, the Anthony Rizzo Family Foundation, the Jaime Erin Follicular Lymphoma Research Consortium, and the University of Miami Sylvester Comprehensive Cancer Center.
PY - 2019/8/13
Y1 - 2019/8/13
N2 - Human germinal center (GC)-associated lymphoma (HGAL) is an adaptor protein expressed in GC B cells. HGAL regulates cell motility and B-cell receptor (BCR) signaling, processes that are central for the successful completion of the GC reaction. Herein, we demonstrate phosphorylation of HGAL by Syk and Lyn kinases at tyrosines Y80, Y86, Y106Y107, Y128, and Y148. The HGAL YEN motif (amino acids 107-109) is similar to the phosphopeptide motif pYXN used as a binding site to the growth factor receptor-bound protein 2 (Grb2). We demonstrate by biochemical and molecular methodologies that HGAL directly interacts with Grb2. Concordantly, microscopy studies demonstrate HGAL-Grb2 colocalization in the membrane central supramolecular activation clusters (cSMAC) following BCR activation. Mutation of the HGAL putative binding site to Grb2 abrogates the interaction between these proteins. Further, this HGAL mutant localizes exclusively in the peripheral SMAC and decreases the rate and intensity of BCR accumulation in the cSMAC. Furthermore, we demonstrate that Grb2, HGAL, and Syk interact in the same complex, but Grb2 does not modulate the effects of HGAL on Syk kinase activity. Overall, the interplay between the HGAL and Grb2 regulates the magnitude of BCR signaling and synapse formation.
AB - Human germinal center (GC)-associated lymphoma (HGAL) is an adaptor protein expressed in GC B cells. HGAL regulates cell motility and B-cell receptor (BCR) signaling, processes that are central for the successful completion of the GC reaction. Herein, we demonstrate phosphorylation of HGAL by Syk and Lyn kinases at tyrosines Y80, Y86, Y106Y107, Y128, and Y148. The HGAL YEN motif (amino acids 107-109) is similar to the phosphopeptide motif pYXN used as a binding site to the growth factor receptor-bound protein 2 (Grb2). We demonstrate by biochemical and molecular methodologies that HGAL directly interacts with Grb2. Concordantly, microscopy studies demonstrate HGAL-Grb2 colocalization in the membrane central supramolecular activation clusters (cSMAC) following BCR activation. Mutation of the HGAL putative binding site to Grb2 abrogates the interaction between these proteins. Further, this HGAL mutant localizes exclusively in the peripheral SMAC and decreases the rate and intensity of BCR accumulation in the cSMAC. Furthermore, we demonstrate that Grb2, HGAL, and Syk interact in the same complex, but Grb2 does not modulate the effects of HGAL on Syk kinase activity. Overall, the interplay between the HGAL and Grb2 regulates the magnitude of BCR signaling and synapse formation.
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U2 - 10.1182/bloodadvances.2018016162
DO - 10.1182/bloodadvances.2018016162
M3 - Article
C2 - 31362927
AN - SCOPUS:85070683848
VL - 3
SP - 2286
EP - 2297
JO - Blood advances
JF - Blood advances
SN - 2473-9529
IS - 15
ER -