Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.7.10.2 (
focal adhesion kinase
)
44,029
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
T cell receptor zeta (TcRzeta)/CD3 ligation initiates a signaling cascade that involves src kinases p56(lck) and zeta-associated protein 70, leading to the phosphorylation of substrates such as TcRzeta, Vav, SH2-domain-containing leukocyte protein 76 (SLP-76), cbl, and p120/130. FYN binding protein (FYB or p120/130) associates with p59(fyn), the TcRzeta/CD3 complex, and becomes tyrosine-phosphorylated in response to receptor ligation. In this study, we report the cDNA cloning of human and murine FYB and show that it is restricted in expression to T cells and myeloid cells and possesses an overall unique hydrophilic sequence with several tyrosine-based motifs, proline-based type I and type II SH3 domain binding motifs, several putative
lysine
/glutamic acid-rich nuclear localization motifs, and a SH3-like domain. In addition to binding the src kinase p59(fyn), FYB binds specifically to the hematopoietic signaling protein SLP-76, an interaction mediated by the SLP-76 SH2 domain. In keeping with this, expression of FYB augmented interleukin 2 secretion from a T cell hybridoma, DC27.10, in response to TcRzeta/CD3 ligation. FYB is therefore a novel hematopoietic protein that acts as a component of the
FYN
and SLP-76 signaling cascades in T cells.
...
PMID:Cloning of a novel T-cell protein FYB that binds FYN and SH2-domain-containing leukocyte protein 76 and modulates interleukin 2 production. 920 19
Uptake of L-[14C]glutamate (L-[14C]GLU) into nonsynaptic mitochondria isolated from rat cerebral hemispheres was measured in the presence of potential modulators of amino acid transport. The L-GLU carrier agonist 0.2 mM L-aspartate (L-ASP) virtually abolished L-GLU uptake (ASP/GLU concentration ratio, 1:1). L-Arginine (L-ARG) inhibited L-GLU uptake in a dose dependent manner over the concentration range 0.1-5 mM to maximum inhibition of 85%. Putrescine or ammonia had no effect, whereas 5 mM creatine and the NO generator, 5 mM sodium nitroprusside, increased the uptake by 73% and 57%, respectively. D-
ARG
was three times less effective in inhibiting L-GLU uptake than L-
ARG
at 5 mM concentration. The L-amino acids ornithine,
lysine
, histidine, tyrosine, phenylalanine, proline, leucine, isoleucine, tryptophan, glycine, methionine, valine, serine, taurine, alanine or cysteine did not affect the uptake when added in concentrations of 2-5 mM. A 14% inhibition of L-GLU uptake was noted in the presence of L-glutamine (L-GLN) (2 mM) or a dicarboxylate carrier ligand, alpha-ketoglutarate (alpha-KG) (5 mM), and a 30% inhibition with a dicarboxylate carrier inhibitor phenylsuccinate (PhSc) (5 mM). The results suggest that L-
ARG
functions as a specific endogenous modulator of cerebral mitochondrial L-GLU transport.
...
PMID:Glutamate uptake is inhibited by L-arginine in mitochondria isolated from rat cerebrum. 924 41
Four Holstein steers (159 kg) surgically fitted with abomasal-infusion cannulas were used in a 4 x 4 Latin square study to test amino acid (AA) and casein (CAS) infusions on nitrogen balance and hormonal status of steers consuming vegetative wheat (Triticum aestivum L.) silage (12.3% CP). Treatments were 5-d infusions of 1) water (CONT), 2) arginine (
ARG
; 13.69 g/d), 3) limiting amino acids (LAA, 13.69 g/d arginine + 10.92 g/d histidine + 28.97 g/d
lysine
+ 10.88 g/d methionine + 16.96 g/d threonine, and 4) Na-CAS (300 g/d). Whole blood was collected for plasma AA, growth hormone (GH), insulin, and IGF-I concentrations. Data were analyzed by ANOVA, and the following orthogonal contrasts were used to separate treatment means: CONT vs
ARG
;
ARG
vs LAA; and LAA vs CAS. Urinary N increased (P < .02) for CAS vs LAA. Arginine increased N retention, as did CAS, compared to LAA. Total plasma essential AA were decreased by arginine. Mean plasma insulin concentrations were increased by CAS (P < .034). Arginine increased mean plasma GH levels, but not IGF-I. The CAS treatment increased (P < .015) IGF-I levels, but not GH. These data suggest that performance of steers fed wheat silage was limited by duodenal AA flow and that arginine was the first-limiting AA. Casein infusion increased plasma insulin and IGF-I, which would explain the improved growth noted in calves and lambs fed forages supplemented with ruminally undegraded protein.
...
PMID:Nitrogen metabolism and hormonal responses of steers fed wheat silage and infused with amino acids or casein. 937 20
We have investigated the influence of the nitric oxide synthase (NOS) substrate, NG-hydroxy-L-arginine (H-ARG) on dopamine (DA) and glutamate (GLU) efflux in vivo using concentric microdialysis probes implanted in the anterior-medial striatum of chloral hydrate-anesthetized rats. Intrastriatal infusion of H-
ARG
(100 microM, 200 microM, or 1 mM for 120 min) increased DA efflux in a dose-dependent fashion. The facilitatory effect of H-
ARG
(1 mM) on DA efflux was abolished following pretreatment (80 min) with the constitutive NOS inhibitor 7-nitroindazole (7-NI, 10 microM) but unaffected by L-NG(1-iminoethyl)
lysine
(100 microM) infusion. As both H-
ARG
(1 mM) and the NO-generator (+/-)-S-nitroso-N-acetylpenicillamine (1 mM) were observed to increase GLU efflux concurrently with the effect on DA efflux, we evaluated the potential intermediary role of GLU in NO-facilitated DA efflux using ionotropic GLU receptor antagonists. Local infusion of dizocilpine maleate (10 microM) or (+/-)-2-amino-3-[3-(carboxymethoxy)-5-methyl-isoxazol-4-yl] propionic acid (100 microM), attenuated the H-
ARG
(1 mM)-induced elevation of extracellular DA levels. Conversely, similar treatment with the kainate receptor antagonist d-gamma-glutamyl-aminomethanesulfonic acid did not alter H-
ARG
-induced DA efflux. To evaluate the regulatory influence of striatal NO on NMDA receptor activation, NMDA (100 microM) was co-perfused with either H-
ARG
(2 mM) or 7-NI (10 microM). While co-perfusion with 7-NI potentiated NMDA-induced DA efflux, similar treatment with H-
ARG
(2 mM) abolished the effect. These results demonstrate that endogenous NO production, stimulated via H-
ARG
-dependent activation of type 1 NOS, enhances striatal DA efflux via an increase in glutamatergic tone on ionotropic GLU-receptors. At higher levels of NOS activation (following H-ARG (2 mM) or NMDA infusion), NO may block glutamatergic neurotransmission via inhibition of NMDA receptor function.
...
PMID:Endogenous nitric oxide facilitates striatal dopamine and glutamate efflux in vivo: role of ionotropic glutamate receptor-dependent mechanisms. 951 28
The Saccharomyces cerevisiae a1 homeodomain is expressed as a soluble protein in Escherichia coli when cultured in minimal medium. Nuclear magnetic resonance (NMR) spectra of previously prepared a1 homeodomain samples contained a subset of doubled and broadened resonances. Mass spectroscopic and NMR analysis demonstrates that the heterogeneity is largely due to a
lysine
misincorporation at the arginine (Arg) 115 site. Arg 115 is coded by the 5'-AGA-3' sequence, which is quite rare in E. coli genes. Lower level mistranslation at three other rare arginine codons also occurs. The percentage of
lysine
for arginine misincorporation in a1 homeodomain production is dependent on media composition. The dnaY gene, which encodes the rare 5'-AGA-3' tRNA(
ARG
), was co-expressed in E. coli with the a1-encoding plasmid to produce a homogeneous recombinant a1 homeodomain. Co-expression of the dnaY gene completely blocks mistranslation of arginine to
lysine
during a1 overexpression in minimal media, and homogeneous protein is produced.
...
PMID:High level, context dependent misincorporation of lysine for arginine in Saccharomyces cerevisiae a1 homeodomain expressed in Escherichia coli. 952 Nov 27
The beta1 integrin adhesion receptors activate signal transduction pathways that induce tyrosine phosphorylation of a variety of substrates. Increased tyrosine phosphorylation is mediated by the beta1 subunit cytoplasmic domain, which consists of 46 amino acids and contains no intrinsic kinase activity. In the H9 T cell line, beta1 integrin engagement leads to the increased tyrosine phosphorylation of three 105 to 115-kDa substrates that are distinct from
focal adhesion kinase
(
FAK
): HEF1 (human enhancer of filamentation 1), a protein with structural homology to p130Cas, and two novel substrates, pp105 and pp115. DNA-mediated gene transfer was used to explore the role of the beta1 cytoplasmic domain in integrin-mediated tyrosine phosphorylation of HEF1, pp105, and pp115 in human T cells. Using a chimeric receptor composed of the cytoplasmic domain of the beta1 integrin subunit and the extracellular and transmembrane domains of the CD2 Ag, we demonstrate that the beta1 cytoplasmic domain is necessary and sufficient for inducing tyrosine phosphorylation of each of these three substrates in H9 T cells. Analysis of a series of beta1 cytoplasmic domain truncations reveals that a truncation of only five amino acids from the carboxyl-terminal end of the beta1 cytoplasmic domain abrogates the ability of the CD2/beta1 chimera to activate tyrosine phosphorylation of HEF1, pp105, or pp115. Thus, the carboxyl-terminal five amino acids,
Lys
-Tyr-Glu-Gly-
Lys
(KYEGK), of the beta1 integrin cytoplasmic domain are critical for the coordinate tyrosine phosphorylation of three non-
FAK
substrates in human T cells.
...
PMID:Structural requirements for beta1 integrin-mediated tyrosine phosphorylation in human T cells. 954 75
Transmission of zucchini yellow mosaic virus (ZYMV) by aphids was examined by introducing mutations within the highly conserved proline-threonine-
lysine
(PTK) motif of the helper component proteinase (HC-Pro) using a cDNA full-length clone. Replacement of proline by alanine (
ATK
) in the PTK motif abolished transmission almost completely both from plants and from membranes. Substitution of the basic
lysine
by glutamic acid (PTE) did not reduce the rate of transmission compared with the wild-type. Replacement of threonine by valine (PVK) or serine (PSK) resulted in a rate of transmission that was lower than that of the wild-type. The rate was lower for PSK than for PVK. Western blot comparison did not permit attribution of HC-Pro functionality in transmission to its level in the host. The HC-Pro of strains that effected transmission (with the wild-type PTK motif, and with the mutated PTE and PVK motifs) could also bind in vitro to virions of ZYMV. HC-Pro with a PSK motif, which was less effective in assisting transmission, could bind only weakly to virions, while HC-Pro of the almost non-transmissible strains (with PAK and
ATK
motifs) did not bind at all. Interestingly, positive binding was recorded for transmission-defective ZYMV-Ct, which has a PTK motif but has glutamic acid instead of
lysine
in the
lysine
-leucine-serine-cysteine (KLSC) motif. These findings support the 'bridge hypothesis', and confirm the binding of the HC-Pro to the virion. The possible role of the PTK and KLSC motifs in binding to the virus and to the mouthparts of the aphid is discussed.
...
PMID:Mutations in the HC-Pro gene of zucchini yellow mosaic potyvirus: effects on aphid transmission and binding to purified virions. 956 86
Bombesin (Bn) receptor subtype 3 (BRS-3) is an orphan receptor that is a predicted member of the heptahelical G-protein receptor family and so named because it shares a 50% amino acid homology with receptors for the mammalian bombesin-like peptides neuromedin B (NMB) and gastrin-releasing peptide. In a recent targeted disruption study, in which BRS-3-deficient mice were generated, the mice developed obesity, diabetes, and hypertension. To date, BRS-3's natural ligand remains unknown, its pharmacology unclear, and cellular basis of action undetermined. Furthermore, there are few tissues or cell lines found that express sufficient levels of BRS-3 protein for study. To define the intracellular signaling properties of BRS-3, we examined the ability of [D-Phe6,beta-Ala11,Phe13, Nle14]Bn-(6-14), a newly discovered peptide with high affinity for BRS-3, and various Bn receptor agonists and antagonists to alter cellular function in hBRS-3-transfected BALB 3T3 cells and hBRS-3-transfected NCI-H1299 non-small cell lung cancer cells, which natively express very low levels of hBRS-3. This ligand stimulated a 4-9-fold increase in [3H]inositol phosphate formation in both cell lines under conditions where it caused no stimulation in untransfected cells and also stimulated an increase in [3H]IP1, [3H]IP2, and 3H]IP3. The elevation of [3H]IP was concentration-dependent, with an EC50 of 20-35 nM in both cell lines. [D-Phe6,beta-Ala11,Phe13,Nle14]Bn-(6-14) stimulated a 2-3-fold increase in [Ca2+]i, a 3-fold increase in tyrosine phosphorylation of p125(
FAK
) with an EC50 of 0.2-0.7 nM, but failed to either stimulate increases in cyclic AMP or inhibit forskolin-stimulated increases. None of nine naturally occurring Bn peptides or three synthetic Bn analogues reported to activate hBRS-3 did so with high affinity. No high affinity Bn receptor antagonists had high affinity for the hBRS-3 receptor, although two low affinity antagonists for gastrin-releasing peptide and NMB receptors, [D-Arg1,D-Trp7,9, Leu11]substance P and [D-Pro4,D-Trp7,9,10]substance P-(4-11), inhibited hBRS-3 receptor activation. The NMB receptor-specific antagonist D-Nal,Cys,Tyr,D-Trp,
Lys
,Val, Cys,Nal-NH2 inhibited hBRS-3 receptor activation in a competitive fashion (Ki = 0.5 microM). Stimulation of p125(
FAK
) tyrosine phosphorylation by hBRS-3 activation was not inhibited by the protein kinase C inhibitor, GF109203X, or thapsigargin, alone or in combination. These results show that hBRS-3 receptor activation increases phospholipase C activity, which causes generation of inositol phosphates and changes in [Ca2+]i and is also coupled to tyrosine kinase activation, but is not coupled to adenylate cyclase activation or inhibition. hBRS-3 receptor activation results in tyrosine phosphorylation of p125(
FAK
), and it is not dependent on activation of either limb of the phospholipase C cascade. Although the natural ligand is not a known bombesin-related peptide, the availability of [D-Phe6,beta-Ala11, Phe13,Nle14]Bn-(6-14), which functions as a high affinity agonist in conjunction with hBRS-3-transfected cell lines and the recognition of three classes of receptor antagonists including one with affinity of 0.5 microM, should provide important tools to assist in the identification of its natural ligand, the development of more potent selective receptor antagonists and agonists, and further exploration of the signaling properties of the hBRS-3 receptor.
...
PMID:Ability of various bombesin receptor agonists and antagonists to alter intracellular signaling of the human orphan receptor BRS-3. 959 99
The
focal adhesion kinase
(
FAK
) protein-tyrosine kinase (PTK) links transmembrane integrin receptors to intracellular signaling pathways. We show that expression of the
FAK
-related PTK, Pyk2, is elevated in fibroblasts isolated from murine fak-/- embryos (FAK-) compared with cells from fak+/+ embryos (FAK+). Pyk2 was localized to perinuclear regions in both FAK+ and
FAK
- cells. Pyk2 tyrosine phosphorylation was enhanced by fibronectin (FN) stimulation of
FAK
- but not FAK+ cells. Increased Pyk2 tyrosine phosphorylation paralleled the time-course of Grb2 binding to Shc and activation of ERK2 in
FAK
- cells. Pyk2 in vitro autophosphorylation activity was not enhanced by FN plating of
FAK
- cells. However, Pyk2 associated with active Src-family PTKs after FN but not poly-L-
lysine
replating of the
FAK
- cells. Overexpression of both wild-type (WT) and kinase-inactive (Ala457), but not the autophosphorylation site mutant (Phe402) Pyk2, enhanced endogenous FN-stimulated c-Src in vitro kinase activity in
FAK
- cells, but only WT Pyk2 overexpression enhanced FN-stimulated activation of co-transfected ERK2. Interestingly, Pyk2 overexpression only weakly augmented
FAK
- cell migration to FN whereas transient
FAK
expression promoted
FAK
- cell migration to FN efficiently compared with FAK+ cells. Significantly, repression of endogenous Src-family PTK activity by p50(csk) overexpression inhibited FN-stimulated cell spreading, Pyk2 tyrosine phosphorylation, Grb2 binding to Shc, and ERK2 activation in the
FAK
- but not in FAK+ cells. These studies show that Pyk2 and Src-family PTKs combine to promote FN-stimulated signaling events to ERK2 in the absence of
FAK
, but that these signaling events are not sufficient to overcome the
FAK
- cell migration defects.
...
PMID:Pyk2 and Src-family protein-tyrosine kinases compensate for the loss of FAK in fibronectin-stimulated signaling events but Pyk2 does not fully function to enhance FAK- cell migration. 977 38
Caspases, a family of cysteine proteases, are the key effector proteins of apoptosis. These proteases cleave cellular proteins and are responsible for the destruction of the cell body during apoptosis. They are also involved in the activation of other proteins, such as cytokines. In this study, we demonstrate a novel function for these proteases. Z-Asp-CH2-DCB (Z-Asp), a general caspase inhibitor, blocked cell spreading on collagen-coated plates in a dose-dependent manner but did not affect cell viability. Caspase 3-like activity but not caspase 1-like activity was detected in adherent cells on both collagen-coated and poly-L-
lysine
-coated plates but not in suspended cells. The caspase 3-like activity was significantly inhibited by Z-Asp. However, only Z-Asp, not specific caspase inhibitors (Z-DEVD for caspase 3, Z-YVAD for caspase 1), was effective in the suppression of cell spreading. The inhibitory effect of Z-Asp was blocked by a phosphokinase C activator, PMA, and a Rho activator, lysophosphatidic acid (LPA), while neither a Rac activator, bradykinin, nor a Cdc42 activator, sphingosine-1 -phosphate, was effective. Immunoprecipitation demonstrated that Z-Asp downregulated the expression of
focal adhesion kinase
(
FAK
) protein, downstream of Rho signaling, in adherent cells. Our results suggest that not caspase 1 or 3 but another yet unknown caspase(s) plays an important role in the maintenance of cytoskeleton integrity via
FAK
protein expression, implying a new function for caspases.
...
PMID:Possible involvement of caspase-like family in maintenance of cytoskeleton integrity. 1008 31
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>