Mitogen-activated protein kinases p42mapk and p44mapk are required for fibroblast proliferation.

Abstract

The mitogen-activated protein kinases (MAP (25) and that sustained activation of MAP kinase during G1 progression appears to be essential for triggering entry into the S phase ofthe cell cycle (25,26). Here, exploiting the use of either MAP kinase antisense or dominant negative alleles, we directly demonstrate that MAP kinase activation is essential for Go-arrested fibroblasts to enter the cell cycle. MATERIALS AND METHODSMaterials. Highly purified human a-thrombin (3200 NIH units/mg) and human recombinant basic fibroblast growth factor (FGF) were generous gifts of J.

Interleukin 1 activates jun N‐terminal kinases JNK1 and JNK2 but not extracellular regulated MAP kinase (ERK) in human glomerular mesangial cells

“…Activated ERKs are thought to play a role in cell proliferation by using overexpression of dominant negative mutants or antisense RNA [15,16]. In contrast we could not measure increased MBP kinase activity in cytosolic extracts or in MonoQ fractions of IL-l-stimulated human mesangial cells under conditions where the phorbol ester PMA or bFGF did induce MAP kinase activity.…”

Elevated urokinase-type plasminogen activator receptor expression in a colon cancer cell line is due to a constitutively activated extracellular signal-regulated kinase-1-dependent signaling cascade

“…Our data demonstrating a role for ERK1 in the regulation of u-PAR expression is reminiscent of other studies implicating this MAPK in the regulation of collagenase I gene expression and cellular transformation. Thus, Pages and co-workers found that the expression of a dominant negative ERK1 construct in the Chinese hamster lung ®broblast cell line CCL39 diminished the stimulation of type I collagenase promoter activity by ®broblast growth factor (Pages et al, 1993). In a separate study, it was shown that the ability of Ras to transform NIH3T3 cells could be reduced by the co-expression of a dominant negative ERK1 (Khosravi-far et al, 1995).…”

BCL-6 is phosphorylated at multiple sites in its serine- and proline-clustered region by mitogen-activated protein kinase (MAPK) in vivo

“…MAPK has been shown to be involved in a broad spectrum of cellular events, including cell growth (Gotoh et al, 1991a, b;Pages et al, 1993;Mansour et al, 1994), di erentiation and maturation (Kosako et al, 1994;Cowley et al, 1994;Kharbanda et al, 1994). It was reported that MAPK is activated during TPAinduced monocytic lineage di erentiation in HL-60 cells (Kharbanda et al, 1994).…”