Limits...
Deficiency of the stress kinase p38alpha results in embryonic lethality: characterization of the kinase dependence of stress responses of enzyme-deficient embryonic stem cells.

Allen M, Svensson L, Roach M, Hambor J, McNeish J, Gabel CA - J. Exp. Med. (2000)

Bottom Line: Comparison of chemical-induced apoptosis processes revealed no significant difference between the p38alpha(1/+) and p38alpha(-/)- ES cells.Therefore, these studies demonstrate that p38alpha is a major upstream activator of MAPKAP kinase 2 and a key component of the IL-1 signaling pathway.However, p38alpha does not serve an indispensable role in apoptosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Respiratory, Allergy, Immunology, Inflammation, and Infectious Diseases, Central Research, Pfizer, Inc., Groton, CT 06340, USA.

ABSTRACT
The mitogen-activated protein (MAP) kinase p38 is a key component of stress response pathways and the target of cytokine-suppressing antiinflammatory drugs (CSAIDs). A genetic approach was employed to inactivate the gene encoding one p38 isoform, p38alpha. Mice for the p38alpha allele die during embryonic development. p38alpha(1/)- embryonic stem (ES) cells grown in the presence of high neomycin concentrations demonstrated conversion of the wild-type allele to a targeted allele. p38alpha(-/)- ES cells lacked p38alpha protein and failed to activate MAP kinase-activated protein (MAPKAP) kinase 2 in response to chemical stress inducers. In contrast, p38alpha(1/+) ES cells and primary embryonic fibroblasts responded to stress stimuli and phosphorylated p38alpha, and activated MAPKAP kinase 2. After in vitro differentiation, both wild-type and p38alpha(-/)- ES cells yielded cells that expressed the interleukin 1 receptor (IL-1R). p38alpha(1/+) but not p38alpha(-/)- IL-1R-positive cells responded to IL-1 activation to produce IL-6. Comparison of chemical-induced apoptosis processes revealed no significant difference between the p38alpha(1/+) and p38alpha(-/)- ES cells. Therefore, these studies demonstrate that p38alpha is a major upstream activator of MAPKAP kinase 2 and a key component of the IL-1 signaling pathway. However, p38alpha does not serve an indispensable role in apoptosis.

Show MeSH
Expression of the four murine p38 isoforms and β-actin in wild-type (+/+) ES cells, wild-type liver (liv), p38α-deficient (−/−) ES cells, and p38α heterozygous (+/−) ES cells. The observed RT-PCR product sizes agreed with the predicted values and are as follows: p38α, 368 bp; p38β, 430 bp; p38δ, 354 bp; p38γ, 632 bp; and β-actin, 540 bp.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2195860&req=5

Figure 3: Expression of the four murine p38 isoforms and β-actin in wild-type (+/+) ES cells, wild-type liver (liv), p38α-deficient (−/−) ES cells, and p38α heterozygous (+/−) ES cells. The observed RT-PCR product sizes agreed with the predicted values and are as follows: p38α, 368 bp; p38β, 430 bp; p38δ, 354 bp; p38γ, 632 bp; and β-actin, 540 bp.

Mentions: To assess whether ES cells express all known p38 family members, RT-PCR was performed on total RNA prepared from wild-type (+/+) DBA/252 ES cells and from two cell lines that demonstrated either heterozygosity (+/−) or the complete absence (−/−) of the p38α allele by Southern blotting. This analysis indicated that wild-type ES cells express mRNA for p38α, β, γ, and δ (Fig. 3). Likewise, total RNA prepared from liver of an adult DBA wild-type mouse contained transcripts encoding each of the four p38 kinases, although the β species appeared to be in low abundance (Fig. 3). In contrast, total RNA isolated from p38α−/− ES cells showed no evidence of the p38α transcript, but these cells maintained expression of p38β, γ, and δ (Fig. 3). p38α1/− ES cells, on the other hand, yielded RNA transcripts corresponding to each of the four p38 kinases. Within the limits of the RT-PCR approach, no obvious change in the relative expression levels of the p38β, γ, and δ species was observed between the +/+ and −/− ES cell lines.


Deficiency of the stress kinase p38alpha results in embryonic lethality: characterization of the kinase dependence of stress responses of enzyme-deficient embryonic stem cells.

Allen M, Svensson L, Roach M, Hambor J, McNeish J, Gabel CA - J. Exp. Med. (2000)

Expression of the four murine p38 isoforms and β-actin in wild-type (+/+) ES cells, wild-type liver (liv), p38α-deficient (−/−) ES cells, and p38α heterozygous (+/−) ES cells. The observed RT-PCR product sizes agreed with the predicted values and are as follows: p38α, 368 bp; p38β, 430 bp; p38δ, 354 bp; p38γ, 632 bp; and β-actin, 540 bp.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195860&req=5

Figure 3: Expression of the four murine p38 isoforms and β-actin in wild-type (+/+) ES cells, wild-type liver (liv), p38α-deficient (−/−) ES cells, and p38α heterozygous (+/−) ES cells. The observed RT-PCR product sizes agreed with the predicted values and are as follows: p38α, 368 bp; p38β, 430 bp; p38δ, 354 bp; p38γ, 632 bp; and β-actin, 540 bp.
Mentions: To assess whether ES cells express all known p38 family members, RT-PCR was performed on total RNA prepared from wild-type (+/+) DBA/252 ES cells and from two cell lines that demonstrated either heterozygosity (+/−) or the complete absence (−/−) of the p38α allele by Southern blotting. This analysis indicated that wild-type ES cells express mRNA for p38α, β, γ, and δ (Fig. 3). Likewise, total RNA prepared from liver of an adult DBA wild-type mouse contained transcripts encoding each of the four p38 kinases, although the β species appeared to be in low abundance (Fig. 3). In contrast, total RNA isolated from p38α−/− ES cells showed no evidence of the p38α transcript, but these cells maintained expression of p38β, γ, and δ (Fig. 3). p38α1/− ES cells, on the other hand, yielded RNA transcripts corresponding to each of the four p38 kinases. Within the limits of the RT-PCR approach, no obvious change in the relative expression levels of the p38β, γ, and δ species was observed between the +/+ and −/− ES cell lines.

Bottom Line: Comparison of chemical-induced apoptosis processes revealed no significant difference between the p38alpha(1/+) and p38alpha(-/)- ES cells.Therefore, these studies demonstrate that p38alpha is a major upstream activator of MAPKAP kinase 2 and a key component of the IL-1 signaling pathway.However, p38alpha does not serve an indispensable role in apoptosis.

View Article: PubMed Central - PubMed

Affiliation: Department of Respiratory, Allergy, Immunology, Inflammation, and Infectious Diseases, Central Research, Pfizer, Inc., Groton, CT 06340, USA.

ABSTRACT
The mitogen-activated protein (MAP) kinase p38 is a key component of stress response pathways and the target of cytokine-suppressing antiinflammatory drugs (CSAIDs). A genetic approach was employed to inactivate the gene encoding one p38 isoform, p38alpha. Mice for the p38alpha allele die during embryonic development. p38alpha(1/)- embryonic stem (ES) cells grown in the presence of high neomycin concentrations demonstrated conversion of the wild-type allele to a targeted allele. p38alpha(-/)- ES cells lacked p38alpha protein and failed to activate MAP kinase-activated protein (MAPKAP) kinase 2 in response to chemical stress inducers. In contrast, p38alpha(1/+) ES cells and primary embryonic fibroblasts responded to stress stimuli and phosphorylated p38alpha, and activated MAPKAP kinase 2. After in vitro differentiation, both wild-type and p38alpha(-/)- ES cells yielded cells that expressed the interleukin 1 receptor (IL-1R). p38alpha(1/+) but not p38alpha(-/)- IL-1R-positive cells responded to IL-1 activation to produce IL-6. Comparison of chemical-induced apoptosis processes revealed no significant difference between the p38alpha(1/+) and p38alpha(-/)- ES cells. Therefore, these studies demonstrate that p38alpha is a major upstream activator of MAPKAP kinase 2 and a key component of the IL-1 signaling pathway. However, p38alpha does not serve an indispensable role in apoptosis.

Show MeSH