Selective activation of mitogen-activated protein (MAP) kinase kinase 3 and p38alpha MAP kinase is essential for cyclic AMP-dependent UCP1 expression in adipocytes.
AuthorsRobidoux J, Cao W, Quan H, Daniel KW, Moukdar F, Bai X, Floering LM, Collins S,
JournalMol Cell Biol
PubMed ID15964803
The sympathetic nervous system regulates the activity and expression of uncoupling protein 1 (UCP1) through the three beta-adrenergic receptor subtypes and their ability to raise intracellular cyclic AMP (cAMP) levels. Unexpectedly, we recently discovered that the cAMP-dependent regulation of multiple genes in brown adipocytes, including Ucp1, occurred through the p38 ... More
Growth-factor receptor-bound protein-2 (Grb2) signaling in B cells controls lymphoid follicle organization and germinal center reaction.
AuthorsJang IK, Cronshaw DG, Xie LK, Fang G, Zhang J, Oh H, Fu YX, Gu H, Zou Y
JournalProc Natl Acad Sci U S A
PubMed ID21508326
'Grb2 (growth-factor receptor-bound protein-2) is a signaling adaptor that interacts with numerous receptors and intracellular signaling molecules. However, its role in B-cell development and function remains unknown. Here we show that ablation of Grb2 in B cells results in enhanced B-cell receptor signaling; however, mutant B cells do not form ... More
T-cell receptor ligation induces distinct signaling pathways in naive vs. antigen-experienced T cells.
AuthorsAdachi K, Davis MM
JournalProc Natl Acad Sci U S A
PubMed ID21205892
Naïve T lymphocytes display weaker and slower responses than antigen-experienced cells for reasons that are not well understood. Here we show that T-cell receptor (TCR) stimulation induces distinct ERK and p38 phosphorylation patterns in naïve and antigen-experienced human T cells, and that these contribute to the differential responses shown by ... More
p38 Mitogen-activated protein kinase plays a stimulatory role in hepatic gluconeogenesis.
AuthorsCao W, Collins QF, Becker TC, Robidoux J, Lupo EG, Xiong Y, Daniel KW, Floering L, Collins S,
JournalJ Biol Chem
PubMed ID16272151
Hepatic gluconeogenesis is essential for maintaining blood glucose levels during fasting and is the major contributor to postprandial and fasting hyperglycemia in diabetes. Gluconeogenesis is a classic cAMP/protein kinase A-dependent process initiated by glucagon, which is elevated in the blood during fasting and in diabetes. In this study, we have ... More
Cell death or survival promoted by alternative isoforms of ErbB4.
AuthorsSundvall M, Veikkolainen V, Kurppa K, Salah Z, Tvorogov D, van Zoelen EJ, Aqeilan R, Elenius K
JournalMol Biol Cell
PubMed ID20943952
The significance of ErbB4 in tumor biology is poorly understood. The ERBB4 gene is alternatively spliced producing juxtamembrane (JM-a and JM-b) and cytoplasmic (CYT-1 and CYT-2) isoforms. Here, signaling via the two alternative ErbB4 JM isoforms (JM-a CYT-2 and JM-b CYT-2) was compared. Fibroblasts expressing ErbB4 JM-a demonstrated enhanced ErbB4 ... More