We examined the links between fibrotic and proliferative pathways for 5-HT 2A receptor in rat mesangial cells. Serotonin (5-hydroxytryptamine, 5-HT) induced transforming growth factor-β1 (TGF-β1) mRNA a concentration-dependent (peak at 30 nM time-dependent fashion. For 10 5-HT, effect was noticeable 1 h maximal by 6 h. Inhibition of 1) protein kinase C (PKC), 2) mitogen- extracellular signal-regulated (MEK1) with 2′-amino-3′-methoxyflavone (PD-90859), 3) (ERK) apigenin attenuated this...

Serotonin (5-HT) is a potent mitogen in many cells types, an action which frequently mediated through pertussis toxin-sensitive G proteins. In the current study, we used pharmacological inhibitors and dominant negative signaling constructs to delineate elements participate activation of MAPK, growth-associated mitogen-activated protein kinase, by human protein-coupled 5-HT1A receptor transfected into CHO-K1 stable manner. The pathway does not directly involve phorbol ester-sensitive kinase C...

Insect cell expression systems are used to characterize signaling components such as G protein-coupled receptors. As such, one must know whether endogenous proteins couple non-native We examined protein linkages after infection of Sporodoptera frugiperda (Sf9) cells with a baculovirus encoding the 5-HT1A receptor. Receptor was confirmed by immunoblot. Some receptors were functional, showing guanine nucleotide-sensitive binding specific agonist ligand...

We constructed an expression vector for a fusion protein [ANG II type 1a receptor-green fluorescent (AT(1a)R-GFP)] consisting of enhanced GFP attached to the COOH terminus rat AT(1a)R. Chinese hamster ovary (CHO) cells transfected with AT(1a)R-GFP demonstrated specific, high-affinity (125)I-labeled ANG binding (IC(50) 21 nM). exposure stimulated sodium-proton exchange and cytoplasmic calcium release similar extent in AT(1a)R or AT(1a)R-GFP; these responses were desensitized by prior...

Serotonin (5-HT) stimulates mitogenesis in rat renal mesangial cells through a G protein-coupled 5-HT 2A receptor. We tested the hypothesis that oxidants might be involved signal transduction pathway linking receptor to extracellular signal-regulated protein kinase (ERK). rapidly increased activity and phosphorylation of ERK. These effects were blocked by antagonist ketanserin. The peak effect was noted at 5–10 min, half-maximal stimulation achieved 10–30 nM 5-HT. Chemical inhibitor...

The hypothesis of this work is that the 'serotonin' or 5-hydroxytryptamine (5-HT)(1A) receptor, which activates extracellular signal-regulated kinase (ERK) through a G(i)betagamma-mediated pathway, does so intermediate actions reactive oxygen species (ROS). Five criteria were shown to support key role for ROS in activation ERK by 5-HT(1A) receptor. (1) Antioxidants inhibit 5-HT. (2) Application cysteine-reactive oxidant molecules ERK. (3) receptor alters cellular redox properties, and...

The type 1 sodium-hydrogen exchanger (NHE-1) is a ubiquitous electroneutral membrane transporter that activated by hypertonicity in many cells. NHE-1 may be an important pathway for Na+ entry during volume restoration, yet the molecular mechanisms underlying osmotic regulation of are poorly understood. In present study we conducted screen signaling molecules could involved hypertonicity-induced activation CHO-K1 Hypertonicity rapidly concentration-dependent manner as assessed proton...

The purposes of this study were to test 1) the relationship between two widely studied mitogenic effector pathways, and 2) hypothesis that sodium-proton exchanger type 1 (NHE-1) is a regulator extracellular signal-regulated protein kinase (ERK) activation in rat aortic smooth muscle (RASM) cells. Angiotensin II (Ang II) 5-hydroxytryptamine (5-HT) stimulated both ERK NHE-1 activities, with preceding ERK. concentration-response curves for 5-HT Ang superimposable processes. Inhibition...

Castration-resistant prostate cancer cells exhibit continued androgen receptor signaling in spite of low levels ligand. Current therapies to block act by inhibiting ligand production or binding. We developed bispecific antibodies capable penetrating and binding outside the ligand-binding domain. Half antibody molecule consists a single-chain variable fragment 3E10, an anti-DNA that enters cells. The other half is version AR441, anti-AR antibody. resulting 3E10-AR441 human LNCaP accumulates...

These experiments tested the hypothesis that signalling elements involved in activation of extracellular signal-regulated protein kinase (ERK) mediate rapid sodium-proton exchange (NHE) fibroblasts when both signals are initiated by a single G protein-coupled receptor, 5-HT1A receptor. Similarities between two processes were comparable concentration-response curves and time-courses, overlapping sensitivity to some pharmacological inhibitors tyrosine kinases (staurosporine genistein),...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAgonist-induced desensitization and phosphorylation of human 5-HT1A receptor expressed in Sf9 insect cellsCanan G. Nebigil, Maria N. Garnovskaya, Shirley J. Casanas, Janet Mulheron, Eric M. Parker, Thomas W. Gettys, John R. RaymondCite this: Biochemistry 1995, 34, 37, 11954–11962Publication Date (Print):September 19, 1995Publication History Published online1 May 2002Published inissue 19 September 1995https://doi.org/10.1021/bi00037a037Request reuse...

We examined the relationship between mitogen-activated MEK (mitogen and extracellular signal-regulated protein kinase kinase) phosphorylation of gene product encoded by retinoblastoma (hereafter referred to as Rb) in vascular smooth muscle cells. Brief treatment cells with 100 nm angiotensin II or 1 μm serotonin resulted serine Rb that was equal magnitude induced treating for 20 h 10% fetal bovine serum (≈3 × basal). There no detectable rapid two close cousins Rb, p107 p130. Phosphorylation...

The presence of G-proteins in the eyespot fraction Chlamydomonas reinhardtii is shown. This capable binding (GTP gamma[35S], possesses GTPase activity and interacts with antibodies raised against a highly conserved peptide most G-proteins' alpha-subunit. Cross-reaction 24-kDa protein detected on immunoblots. Using an antiserum prepared from vertebrate beta-subunit peptide, two additional proteins apparent Mr 21 29 kDa could be revealed. light-dependence extraction membranes results make it...

Angiotensin II (AII) binds to G protein-coupled receptor AT 1 and stimulates extracellular signal-regulated kinase (ERK), leading vascular smooth muscle cells (VSMC) proliferation. Proliferation of mammalian is tightly regulated by adhesion the matrix, which occurs via integrins. To study cross-talk between receptor- integrin-induced signaling, we hypothesized that integrins are involved in AII-induced proliferation VSMC. Using Oligo GEArray quantitative RT-PCR, established messages for α -,...

Bradykinin (BK) has been implicated in the regulation of renal function. Activation extracellular signal-regulated protein kinase (ERK1/2) demonstrated several models toxic or proliferative injury. We studied activation ERK1/2 by BK a cell model most distal part nephron, inner medullary collecting duct (mIMCD-3) cells. Exposure mIMCD-3 cells to (10⁻¹⁰–10⁻⁵ M) resulted concentration-dependent increase tyrosine phosphorylation ERK1/2, with maximal effect at...

Second messenger coupling of the 5-hydroxytryptamine (5-HT)2A receptor endogenous to cultured rat glomerular mesangial cells was studied. 5-HT induced an increase in total inositol phosphate levels (EC50 = 265 +/- 55 nM, maximum stimulation 150 23%). That effect sensitive antagonists 5-HT2A and insensitive pertussis toxin at doses that eliminated detectable substrate, as determined by membrane ADP-ribosylation. Surprisingly, also inhibition forskolin-stimulated cAMP accumulation (55 6%, IC50...

We used a cultured murine cell model of the inner medullary collecting duct (mIMCD-3 cells) to examine regulation ubiquitous sodium-proton exchanger, Na+/H+ exchanger isoform 1 (NHE-1), by prototypical G protein-coupled receptor, bradykinin B2receptor. Bradykinin rapidly activates NHE-1 in concentration-dependent manner as assessed proton microphysiometry quiescent cells and 2′-7′-bis[2-carboxymethyl]-5(6)-carboxyfluorescein fluorescence measuring accelerated rate pHi recovery from an...

Previous studies have demonstrated the presence of mitogenic serotonin [i.e., 5-hydroxytryptamine (5-HT)] receptors on glomerular mesangial cells and linked those to a complicated array intracellular autocrine/paracrine signaling pathways [T. Knauss H. E. Abboud. Am. J. Physiol. 251 (Renal Fluid Electrolyte 20): F844-F850, 1986; N. Takuwa, M. Ganz, Y. R. B. Sterzel, Rasmussen. 257 26): F431-F439, 1989]. Those suggested that subtype 5-HT receptor is member 5-HT2 family, which consists three...

The sodium/proton exchanger type 1 (NHE-1) plays an important role in the proliferation of vascular smooth muscle cells (VSMC). We have examined regulation NHE-1 by two potent mitogens, serotonin (5-HT, 5-hydroxytryptamine) and angiotensin II (Ang II), cultured VSMC derived from rat aorta. 5-HT Ang rapidly activated via their G protein-coupled receptors (5-HT(2A) AT(1)) as assessed proton microphysiometry quiescent measurements intracellular pH on a FLIPR (fluorometric imaging plate reader)....