Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
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Target Concepts:
Gene/Protein
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Query: EC:2.7.11.1 (
protein kinase
)
81,284
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We previously established that n-3 FA status in membrane phospholipids influences the biosynthesis and accumulation of PS in neuronal tissues. We also demonstrated that neuronal apoptosis under adverse conditions is prevented by DHA enrichment in a PS-dependent manner. In this study, we examined the effect of a structural analog of DHA, docosapentaenoic acid (22:5n-6,
DPA
), which accumulates in neuronal membranes during n-3 FA deficiency. We observed that enrichment of neuronal cells with
DPA
increased the total PS content in comparison to nonenriched control. However, the increase was significantly less than that observed in DHA-enriched cells, primarily due to the fact that the 18:0,22:5n-6 species was not accumulated as effectively as 18:0,22:6n-3 in PS. As was the case with DHA,
DPA
enrichment also protected against cell death induced by staurosporine treatment in Neuro 2A cells, but to a lesser extent. These data indicate that provision of
DPA
in place of DHA is sufficient neither for fully supporting PS accumulation nor for cell survival. The in vitro interaction between
Raf-1
and membrane was affected not only by the PS content but also by the fatty acyl composition in PS. The reduction of PS concentration as well as the substitution of 18:0,22:6 with 16:0,18:1 in the liposome considerably reduced the interaction with
Raf-1
. These data suggest that depletion of DHA from neuronal tissues may have a compounding effect on
Raf-1
translocation in growth factor signaling. The fact that
DPA
cannot fully support the protective role played by DHA may provide a basis for the adverse effect of n-3 FA deficiency on neuronal development and function.
...
PMID:Effects of docosapentaenoic acid on neuronal apoptosis. 1284 93
Prostaglandins (PGs), particularly PGE(2), can stimulate bone resorption and formation and auto-amplify their effects by inducing cyclooxygenase (COX)-2. We examined the role of different PG receptors in stimulating cAMP production and COX-2 expression in murine calvarial osteoblasts. Cells were obtained from PGE(2) receptor (EP2R and EP4R) wild-type and knockout (KO) mice and from mice transgenic for the COX-2 promoter fused to a luciferase reporter. We analyzed effects of selective agonists, EP2A and EP4A, for EP2R and EP4R, which mediate the increase in cAMP in response to PGE(2). We also tested agonists for other PGE(2) receptors (EP1A and EP3A) and for prostacyclin (IPA), prostaglandin D(2) (
DPA
), thromboxane (TPA), and prostaglandin F(2alpha) (FPA) receptors. PGE(2) and EP2A were the most effective stimulators of cAMP production. EP4A, IPA, and
DPA
produced smaller responses, and EP1A, EP3A, FPA, and TPA were ineffective. In EP2R KO cells, cAMP responses to PGE(2) were reduced by 80%, and responses to EP2A were abrogated. In EP4R KO cells, cAMP responses to PGE(2) and EP2A showed a small reduction, while the response to EP4A was abrogated. Pretreatment with PGE(2), EP2A, or EP4A down-regulated the subsequent response to the respective ligands. COX-2 induction was measured by increased luciferase activity and mRNA expression. PGE(2) was the most effective agonist; EP2A and another selective EP2R agonist, butaprost, showed similar efficacy, and EP4A was less effective. EP2A and EP4A effects on luciferase activity were additive, and effects of the combination were similar to PGE(2) itself. IPA, TPA, and
DPA
produced 2- to 6-fold increases in COX-2 expression. FPA was a weak agonist, while EP1A and EP3A were inactive. Treatment with specific inhibitors indicated that PGE(2), EP2A, and EP4A induced COX-2 expression largely through
protein kinase A
(
PKA
). We conclude that the PG induction of COX-2 in this system generally paralleled effects on cAMP production and was mediated predominantly via the
PKA
pathway.
...
PMID:Stimulation of cAMP production and cyclooxygenase-2 by prostaglandin E(2) and selective prostaglandin receptor agonists in murine osteoblastic cells. 1512 Oct 14
A cotton fiber cDNA and its genomic sequences encoding an A-type
cyclin-dependent kinase
(GhCDKA) were cloned and characterized. The encoded GhCDKA protein contains the conserved cyclin-binding, ATP binding, and catalytic domains. Northern blot and RT-PCR analysis revealed that the GhCDKA transcript was high in 5-10
DPA
fibers, moderate in 15 and 20
DPA
fibers and roots, and low in flowers and leaves. GhCDKA protein levels in fibers increased from 5-15
DPA
, peaked at 15
DPA
, and decreased from 15 t0 20
DPA
. The differential expression of GhCDKA suggested that the gene might play an important role in fiber development. The GhCDKA sequence data was used to develop single nucleotide polymorphism (SNP) markers specific for the CDKA gene in cotton. A primer specific to one of the SNPs was used to locate the CDKA gene to chromosome 16 by deletion analysis using a series of hypoaneuploid interspecific hybrids.
...
PMID:A cotton-fiber-associated cyclin-dependent kinase a gene: characterization and chromosomal location. 2274 34