Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein tyrosine kinases (PTKs) are closely related to cell growth, proliferation and differentiation. In keratinocytes, various growth factor receptors and cytosolic proteins, including the EGF and IGF receptors, the proteins of the src family and others, exhibit PTK activity. In psoriatic epidermis an increased level of EGF receptors and their ligand TGF-alpha has been found, and this is thought to be one reason for the pathological hyperproliferation of keratinocytes in this disease. Oral treatment with cyclosporin A (CsA) and FK506 or topical treatment with dithranol lead to an improvement in psoriasis. In the present study we examined the effect of these three drugs on the cellular content of phosphorylated tyrosines in highly proliferative HaCaT keratinocytes. HaCaT keratinocytes can be used as a model for highly proliferative epidermis, e.g. psoriatic epidermis. CsA had no effect whereas FK506 and dithranol reduced the phosphorylation of tyrosine residues in HaCaT keratinocytes. The activation of serine/threonine protein kinase C (PKC) is known to downregulate PTKs. Therefore we incubated keratinocytes with the selective PKC inhibitor Ro 31-8220 in addition to the other drugs. Only after the addition of Ro 31-8220 to FK506-treated keratinocytes was the phosphotyrosine (p-tyr) level elevated, but this was only one-third of the increase measured without additional therapeutic drugs. We assume that an induction of PKC alone is not responsible for the reduced p-tyr level after treatment with dithranol and FK506.(ABSTRACT TRUNCATED AT 250 WORDS)
Arch Dermatol Res 1995
PMID:Cyclosporin A, FK506 and dithranol after tyrosine-specific protein phosphorylation in HaCaT keratinocytes. 754 Nov 91

Cellular activity of cyclic adenosine monophosphate (cAMP)-degrading phosphodiesterases (PDEs) is of crucial importance for the regulation of cAMP levels. However, PDE isoenzymes in human keratinocytes have not been characterized previously. In the present study, the PDE isoenzyme activity profile of the human keratinocyte cell line HaCaT was investigated by PDE activity measurements. In addition, the cAMP-mediated regulation of PDE activities was examined. The isoenzymes PDE IV and PDE V activities were identified in HaCaT cell homogenates by activity measurements and were found to be preferentially located in the soluble fraction. Long-term exposure of HaCaT cells to cAMP-elevating agents (e.g., rolipram, salbutamol, forskolin) triggered a maximum threefold up-regulation of PDE IV activity, whereas PDE V activity was not affected. The PDE IV inhibitor rolipram synergistically amplified PDE IV up-regulation by beta 2-receptor agonists. Experiments applying protein kinase A activators and inhibitors as well as actinomycin D and cycloheximide indicated that de novo mRNA and protein synthesis were at least partly involved in PDE IV up-regulation. Functionally, the enhanced PDE IV activity was reflected by an impaired cAMP response to salbutamol. This hyporesponsiveness toward the beta 2-adrenoceptor agonists was partly reversed by rolipram. This study describes a cAMP-dependent long-term up-regulation of PDE IV in HaCaT cells, which is at least partly reflected by a simultaneous reduced cAMP response to a beta-agonist.
J Invest Dermatol 1995 Jul
PMID:Identification of phosphodiesterase IV activity and its cyclic adenosine monophosphate-dependent up-regulation in a human keratinocyte cell line (HaCaT). 761 79

It has recently become clear that cyclin-dependent kinase (cdk) complex regulates the cell cycle by phosphorylating Rb protein, a tumor suppressor protein. It is likely that this complex is a target of various growth factors and anti-growth factors (UV, TGF-beta etc.) in keratinocyte (KC). It has also been suggested that abnormalities in the cell cycle regulating mechanism such as increased activity of cyclin-cdk due to mutation of p53, a tumor suppressor gene, and overexpression of cyclin D may be concerned with carcinogenesis of KC. Thus, recent studies indicate that the cyclin-cdk complex is a common target of proliferation and carcinogenesis in KC.
Exp Dermatol 1995 Feb
PMID:Cell cycle regulators in the keratinocyte (cyclin-cdk). 775 27

The benign dermal nevus can be transformed into malignant melanoma. The possibility that the transformation process is accompanied with enhanced casein kinase II (CK II) activity was investigated. The tissue samples were obtained by incisional biopsy, homogenized and ultracentrifuged. The supernatant was injected onto a Mono Q column. CK II was monitored with [gamma-32P]GTP and its specific substrate RRREEETEEE. The CK II stimulators, spermine and polylysine, the inhibitors heparin, quercetin, poly (Glu-Tyr) 4:1 and 2,3-bisphosphoglycerate were used for identification. CK II activity in metastatic melanoma samples was about 2.5-fold higher than in dermal nevus. These results support our hypothesis that CK II takes a central role in the non-transformed and transformed skin proliferation.
J Dermatol Sci 1994 Aug
PMID:Enhanced casein kinase II activity in metastatic melanoma. 794 92

The low cost, high versatility, and reliable production of bacterially produced recombinant antibody fragments speeds up the development of tumor-targeting agents. High-quality recombinant anti-melanoma antibodies are much sought after in the scientific community. We cloned the murine antibody 225.28S, currently used in radioimmunoimaging of human melanoma lesions, in single-chain Fv configuration (scFv) for soluble expression in bacteria. The recombinant antibody fragment conserved the binding specificity of the parental antibody. In order to arm the scFv(225.28S) with biologically useful effector functions, we developed vectors for soluble expression of scFv(225.28S) in bacteria that allow both covalent and noncovalent chemical antibody modification at positions that do not interfere with antigen binding. An expression vector was developed that appends a cysteine residue at the C-terminal extremity of the recombinant antibody, thus allowing reaction with thiol-specific reagents, including 99mTc labeling, at a position that does not interfere with antigen binding. The scFv(225.28S) was also successfully expressed with a casein kinase II substrate tag that enables efficient and stable 32P labeling. For noncovalent antibody modification, we developed an expression vector that appends the human calmodulin gene at the C-terminal extremity of scFv(225.28S). The calmodulin domain is poorly immunogenic and can be targeted with chemically modified high-affinity calmodulin ligands. The recombinant anti-human melanoma antibodies described in this article should prove useful "building blocks" for the development of anti-melanoma diagnostic and therapeutic strategies.
J Invest Dermatol 1996 Aug
PMID:Recombinant anti-human melanoma antibodies are versatile molecules. 875 57

Mitogen-activated protein (MAP) kinases are proline-directed kinases which are downstream components of a pathway involving p21ras and the serine/threonine kinase Raf-1. They represent an important link between the signal transduction processes at the level of the plasma membrane and the final nuclear events. Not only various growth factors and cytokines, but also other signals such as UV-light or extracellular matrix components are able to activate MAP kinases. We believe that the MAP kinase cascade may play a significant role in regulating cell proliferation and differentiation in human epidermis. In this review we summarize the rapidly increasing knowledge in this field of signal transduction and discuss some very recent results on MAP kinases and their role in skin biology.
J Dermatol Sci 1996 Sep
PMID:The mitogen-activated protein kinases system (MAP kinase cascade): its role in skin signal transduction. A review. 888 31

Wild-type p53 accumulation induced by DNA damaging agents such as ultraviolet (UV) radiation, gamma-irradiation and drugs, may arrest the cell cycle until DNA damage is repaired. p21Waf1/Cip1 is a cyclin-dependent kinase (CDK) inhibitor induced by wild-type p53. CDK is activated by cyclin and progresses the cell cycle. On the other hand, CDK inhibitors inhibit CDK activity to arrest the cell cycle. Thus, p21Waf1/Cip1 is thought to mediate the signal of p53 induced by DNA damaging agents to arrest the cell cycle. p21Waf1/Cip1 is induced by wild-type, but not mutant p53. To investigate p21Waf1/Cip1 regulation by p53 in epidermis in vivo, immunohistochemical staining of p21Waf1/Cip1 and p53 were conducted in chronically sun-exposed normal epidermis and in neoplastic epidermis, p21Waf1/Cip1 expression was found to be coincident with the p53-positive regions or not coincident with the p53-positive regions in chronically sun-exposed normal epidermis, whereas there was only low or undetectable p21Waf1/Cip1 expression in any regions including the p53-positive regions of solar keratosis and squamous cell carcinoma of the skin. This suggests that wild-type p53 and p21Waf1/Cip1 may play a part in chronically sun-exposed normal epidermis response to UV exposure, whereas p21Waf1/Cip1 cannot be induced by mutated p53 in solar keratosis and squamous cell carcinoma of the skin.
Br J Dermatol 1996 Nov
PMID:Coexpression of p21Waf1/Cip1 and p53 in sun-exposed normal epidermis, but not in neoplastic epidermis. 920 32

We have investigated the possibility that protein kinase A (PKA) may play a part in regulating the activity of human and mouse hair follicles in whole organ culture. Human hair follicles were isolated from facial skin by microdissection, and hair follicle and hair fibre length measurements were made daily during suspension culture. Incubation of human hair follicles with dibutyryl-cAMP (db-cAMP) resulted in a dose-dependent inhibition of total cumulative follicle growth (IC50 = 100 mumol/L, 85% inhibition at 1 mmol/L). db-cAMP (0.5 mmol/L) also caused a rapid, partial inhibition of follicular DNA synthesis (20.3% inhibition at 6 h, 48.0% inhibition at 24 h). Human hair follicle growth was inhibited by the phosphodiesterase inhibitors 3-isobutyl-1-methylxanthine and Ro 20-1724, and by the adenylate cyclase activator, forskolin. In addition, db-cAMP inhibited DNA synthesis in organ cultures of whisker follicles isolated from neonatal mice by microdissection. Taken together, these findings indicate that agents which increase cAMP levels are potent inhibitors of human and mouse hair follicle growth, and suggest that PKA may play a part in the regulation of hair follicle activity in vivo.
Br J Dermatol 1997 Jun
PMID:Evidence that activation of protein kinase A inhibits human hair follicle growth and hair fibre production in organ culture and DNA synthesis in human and mouse hair follicle organ culture. 921 16

Monomethylfumarate (MMF), the most active metabolite of the new antipsoriasis drug Fumaderm, stimulates an anti-inflammatory mediator profile in human leucocytes and inhibits the proliferation of keratinocytes. These effects of MMF on cells in vitro may in part explain the beneficial action of Fumaderm in patients. In addition, we have reported that MMF stimulates an increase in the intracellular free Ca2+ concentration ([Ca2+]i) and the cyclic adenosine monophosphate (cAMP) concentration in granulocytes and keratinocytes. Because Ca2+ and cAMP control many physiological cellular responses, including cell proliferation and inflammatory mediator production, the present study focused on the intracellular signal transduction pathway which links interaction between MMF and granulocytes with increases in [Ca2+]i and the cAMP concentration. The increase in [Ca2+]i in granulocytes after MMF depended both on extracellular Ca2+ and Ca2+ from intracellular stores. Ca2+ is essential for the increase in the cAMP concentration after stimulation with MMF. The results found for pharmacological inhibitors of various protein kinases suggest that a staurosporine-sensitive protein kinase different from protein kinase C (PKC) and protein kinase A is involved in the MMF-induced increase in [Ca2+]i in granulocytes. As MMF activated protein tyrosine kinase (PTK), and inhibition of this protein kinase partially reduced the increase in [Ca2+]i in granulocytes, PTK activity most likely is involved. In addition, activation of protein kinase histone 4 (PKH4) probably plays a part in the MMF-stimulated increase in [Ca2+]i in granulocytes as well. As MMF stimulated an increase in the GTP-ase activity of membranes and pertussis toxin (PTX) inhibited the increase in the [Ca2+]i and PKH4 activity of granulocytes stimulated by this compound, it is concluded that MMF activates PTX-sensitive G proteins. Competition binding studies with radiolabelled dimethylfumarate (DMF) and unlabelled DMF and MMF revealed the presence of specific binding sites for methylated fumarates on granulocytes. In summary, MMF binds to specific sites on the plasma membrane of cells. This interaction activates pertussis toxin-sensitive G proteins which then stimulate an increase in PTK and PKH4 activity. These protein kinases may regulate the rise in [Ca2+]i and the intracellular cAMP concentration. Elevated [Ca2+]i and intracellular cAMP concentration stimulate protein kinases that regulate transcription factors. Activation of these factors results in induction of downstream gene expression and thus controls cell functions, e.g. cell proliferation and production of inflammatory mediators, as has been found for cells incubated with MMF.
Br J Dermatol 1997 Jul
PMID:Intracellular signalling by binding sites for the antipsoriatic agent monomethylfumarate on human granulocytes. 927 27

Although the TGF-beta family of growth factors probably regulates skin and hair follicle development, its exact role is still quite ill-defined. Here, we characterize the correlative expression pattern of the interdependent high affinity receptor proteins for TGF-beta1 and TGF-beta3, TGF-beta receptor type I (TGF-betaRI) and TGF-beta receptor type II (TGF-betaRII), during hair follicle development and cycling in C57BL/6 mice. During neonatal follicle development, TGF-betaRII immunoreactivity is confined to epithelial cells. Focal epidermal TGF-betaRII expression is seen even before actual hair placode formation. In contrast to the TGF-betaRII immunoreactivity in the outer root sheath, precortical hair matrix and inner root sheath cells were TGF-betaRII negative during hair bulb morphogenesis. TGF-betaRI (Alk-5) immunoreactivity largely overlapped the TGF-betaRII expression pattern, but was more widespread. During hair follicle cycling in adolescent mice, TGF-betaRII immunoreactivity was restricted to follicles, and was strikingly hair cycle dependent (maximal immunoreactivity: anagen VI and early catagen). Again, TGF-betaRI (Alk-5) immunoreactivity co-localized with TGF-betaRII immunoreactivity, but was more extensive. Reverse transcriptase polymerase chain reaction analysis of TGF-betaRII mRNA confirmed peak transcript levels in back skin with most hair follicles in the anagen VI-catagen transformation. mRNA levels of TGF-betaRI (Alk-5) did not vary significantly during the hair cycle, whereas those of TGF-betaRI (threonine-serine kinase 7 L) declined during early anagen, and were maximal during the anagen-catagen transition. This provides a basis for defining the choreography of TGF-beta-related signalling during hair follicle morphogenesis and cycling, introduces intraepidermal TGF-betaRII immunoreactivity as a marker for imminent follicle development, and supports the concept that both TGF-betaRII and TGF-betaRI stimulation is involved in, but not restricted to, the control of catagen induction.
J Invest Dermatol 1997 Oct
PMID:Transforming growth factor-beta receptor type I and type II expression during murine hair follicle development and cycling. 932 84


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