Interleukin-4 mediates STAT6 activation in 3T3-L1 preadipocytes but not adipocytes.
STAT6 is abundantly expressed in 3T3-L1 preadipocytes and adipocytes but activating ligands are not well defined. In this report, we provide evidence that interleukin 4 (IL-4) induced JAK2-mediated STAT6 tyrosine phosphorylation and DNA binding in 3T3-L1 preadipocytes but not in 3T3-L1 adipocytes. Loss of IL-4-mediated STAT6 tyrosine phosphorylation occurred 2 days after preadipocytes were induced to differentiate into adipocytes but when cells remained phenotypically preadipocytes. 3T3-L1 adipocytes were still responsive to IL-4 through tyrosine phosphorylation of other cellular proteins. We conclude that IL-4 signals through STAT6 in 3T3-L1 preadipocytes but not in 3T3-L1 adipocytes. This differentiation-dependent loss of STAT6 activation may be critical for distinct biological effects of IL-4 in 3T3-L1 preadipocytes and adipocytes.
Deng
J
J
Department of Nutrition, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
Hua
K
K
Lesser
S S
SS
Greiner
A H
AH
Walter
A W
AW
Marrero
M B
MB
Harp
J B
JB
D016475:3T3 Cells; D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation; D015847:Interleukin-4 / Q000494:pharmacology*; D053614:Janus Kinase 2; D051379:Mice; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D050800:STAT6 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
D011518:Proto-Oncogene Proteins; D050800:STAT6 Transcription Factor; C494100:Stat6 protein, mouse; D015534:Trans-Activators; D015847:Interleukin-4; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C507926:Jak2 protein, mouse; D053614:Janus Kinase 2