| First Author | Chang JW | Year | 2009 |
| Journal | Int Immunol | Volume | 21 |
| Issue | 12 | Pages | 1351-61 |
| PubMed ID | 19880579 | Mgi Jnum | J:155458 |
| Mgi Id | MGI:4414575 | Doi | 10.1093/intimm/dxp106 |
| Citation | Chang JW, et al. (2009) hnRNP-K is a nuclear target of TCR-activated ERK and required for T-cell late activation. Int Immunol 21(12):1351-61 |
| abstractText | Sustained extracellular signal-regulated kinase (ERK)-signaling plays a critical role in T-cell-mediated IL-2 production. Although many downstream targets are known for ERK, details remain unknown about which molecules play functional roles in IL-2 production. Here, we addressed this question using proteomic analysis of nuclear proteins from TCR-activated T cells and identified hnRNP-K as one of the ERK targets essential for IL-2 production. hnRNP-K was previously shown by others to be a direct substrate of ERK and form complexes with multiple signaling proteins as well as DNA and RNA. Our data showed a clear ERK-dependent increase in one form of hnRNP-K after TCR stimulation. Small interfering RNA-mediated gene knockdown of hnRNP-K expression abrogated IL-2 production by T cells. Moreover, reduction of hnRNP-K expression caused a notable increase in proteolysis of Vav1, a binding target of hnRNP-K. Since Vav1 is an essential molecule for T-cell activation, the data suggest that ERK signaling is required for T-cell activation partly by inhibiting activation-induced proteolysis of Vav1. |
