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Search for: from 1 [map kinase cascade.mp. [mp=ti, ab, tx, ct, rw, sh]] keep
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Citations: 1
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Database
Journals@Ovid
Accession Number
00004210-200008000-00005.
Author
Gold, Michael R; Ingham, Robert J; McLeod, Sarah J; Christian, Sherri L; Scheid,
Michael P; Duronio, Vincent; Santos, Lorna; Matsuuchi, Linda
Institution
Authors' addresses Michael R. Gold(1), Robert J. Ingham(1), Sarah J. McLeod(1),
Sherri L. Christian(1), Michael P. Scheid(2), Vincent Duronio(2), Lorna Santos(3),
Linda Matsuuchi(3), (1)Department of Microbiology and Immunology, University
of British Columbia, Vancouver, British Columbia, Canada. (2)Department of
Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
(3)Department of Zoology, University of British Columbia, Vancouver, British
Columbia, Canada.
Title
Targets of B-cell antigen receptor signaling: the phosphatidylinositol 3-kinase/Akt/glycogen
synthase kinase-3 signaling pathway and the Rap1 GTPase.[Miscellaneous Article]
Source
Immunological Reviews. 176:47-68, August 2000.
Local Message
*ALL AT: UAMS*
Abstract
Summary: In this review, we discuss the role of phosphatidylinositol 3-kinase
(PI3K) and Rap1 in B-cell receptor (BCR) signaling. PI3K produces lipids that
recruit pleckstrin homology domain-containing proteins to the plasma membrane.
Akt is a kinase that the BCR activates in this manner. Akt phosphorylates
several transcription factors as well as proteins that regulate apoptosis
and protein synthesis. Akt also regulates glycogen synthase kinase-3, a kinase
whose substrates include the nuclear factor of activated T cells (NF-AT)c1
and [beta]-catenin transcriptional activators. In addition to Akt, PI3K-derived
lipids also regulate the activity and localization of other targets of BCR
signaling. Thus, a key event in BCR signaling is the recruitment of PI3K to
the plasma membrane where its substrates are located. This is mediated by
binding of the Src homology (SH) 2 domains in PI3K to phosphotyrosine-containing
sequences on membrane-associated docking proteins. The docking proteins that
the BCR uses to recruit PI3K include CD19, Cbl, Gab1, and perhaps Gab2. We
have shown that Gab1 colocalizes PI3K with SH2 domain-containing inositol
phosphatase (SHIP) and SHP2, two enzymes that regulate PI3K-dependent signaling.
In contrast to PI3K, little is known about the Rap1 GTPase. We showed that
the BCR activates Rap1 via phospholipase C-dependent production of diacylglycerol.
Since Rap1 is thought to regulate cell adhesion and cell polarity, it may
be involved in B-cell migration.
(C) 2000 Munksgaard International Publishers Ltd.