Search results for "Enzyme-linked receptor"
showing 8 items of 18 documents
Anti-Idiotypic Antibodies Against the Kinin Receptor
1992
Three sets of monoclonal antibodies against bradykinin (MBK1, MBK2, and MBK3) were generated by somatic cell fusion, characterized by their peptide specificity, and compared with the known ligand specificity of the kinin receptor subtypes. By these criteria, the paratope of MBK3 resembled the B 2 receptor binding site, whereas MBK1 shared principal binding characteristics with the B 1 receptor. Anti-idiotypic antibodies against MBK1, MBK2, and MBK3 were raised in rabbit and sheep
A New Type of Cytokine Receptor Antagonist Directly Targeting gp130
1998
The interleukin-6-type family of cytokines bind to receptor complexes that share gp130 as a common signal-transducing subunit. So far, receptor antagonists for interleukin-6-type cytokines have been constructed that still bind to the specific ligand binding subunit of the receptor complex, but have lost the ability to stimulate gp130. Such receptor antagonists compete for a specific receptor of a member of the cytokine family. Interleukin-6 only binds to gp130 when complexed with the interleukin-6 receptor that exists as a membrane bound and soluble molecule. Here we have constructed fusion proteins that consist of the soluble form of the human interleukin-6 receptor covalently linked to in…
Ligand-induced phosphorylation/dephosphorylation of the endogenous bradykinin B2 receptor from human fibroblasts.
1996
We have studied the ligand-induced phosphorylation/dephosphorylation of the bradykinin B2 receptor endogenously expressed in human HF-15 fibroblasts. An antiserum (AS346) to a synthetic peptide (CRS36), derived from the extreme carboxyl terminus of the human B2 receptor, precipitated the receptor from solubilized membranes of HF-15 cells that had been labeled with [32P]orthophosphate. A low basal level of B2 receptor phosphorylation was found in the absence of a ligand. Stimulation of the cells with the B2 receptor agonists bradykinin, [Lys0,Hyp3]bradykinin, kallidin, and T-kinin resulted in a rapid and efficient phosphorylation of the receptor. The B2 receptor antagonist HOE140 and the B1 …
Agonist and antagonist-dependent internalization of the human vasopressin V2 receptor.
1998
Abstract In this report we demonstrate that in HEK293 cells stably expressing the human V2vasopressin receptor, ligand-induced internalization of the hormone receptor occurs via the clathrin-dependent pathway. Studies of receptor trafficking either by direct visualization of the V2receptor by confocal microscopy or binding experiments show a rapid internalization (half-time 6–7 min). Blocking of the clathrin-dependent pathway by hypertonic sucrose increased vasopressin-induced cellular cAMP production and decreased the desensitization of the V2receptor–adenylyl cyclase system. Thus, internalization appears to be a major regulatory mechanism terminating vasopressin action in HEK293 cells. Tw…
A mutation in the second intracellular loop of the pituitary adenylate cyclase activating polypeptide type I receptor confers constitutive receptor a…
2000
AbstractThe pituitary adenylate cyclase activating polypeptide (PACAP) type I receptor belongs to the glucagon/secretin/vasoactive intestinal polypeptide (VIP) receptor family. We mutated and deleted an amino acid residue (E261) which is located within the second intracellular loop of the rat PACAP type I receptor and which is highly conserved among the receptor family. The wild-type receptor and the mutant receptors were efficiently expressed at the surface of COS-7 cells at nearly the same level and revealed the same high affinity for the agonist PACAP-27. The cAMP contents of COS cells transfected with the E261A, E261Q, and the deletion mutant receptor were 4.6-, 5.7-, and 6.7-fold highe…
New Melanocortin 1 Receptor Binding Motif Based on the C-Terminal Sequence of ?-Melanocyte-Stimulating Hormone
2006
The C-terminal tripeptide of the alpha-melanocyte stimulating hormone (alpha-MSH11-13) possesses strong antiinflammatory activity without known cellular target. In order to better understand the structural requirements for function of such motif, we designed, synthesized and tested out Trp- and Tyr-containing analogues of the alpha-MSH11-13. Seven alpha-MSH11-13 analogues were synthesized and characterized for their binding to the melanocortin receptors recombinantly expressed in insect (Sf9) cells, infected with baculovirus carrying corresponding MC receptor DNA. We also tested these analogues on B16-F1 mouse melanoma cells endogenously expressing the MC1 receptor for binding and for abili…
Chapter 4 Cholesterol and steroid hormones: modulators of oxytocin receptor function
2002
The function and physiological regulation of the oxytocin-receptor system is strongly steroid-dependent. This is, unexpectedly, only partially reflected by the promoter sequences in the oxytocin receptor and favors the idea that posttranscriptional mechanisms may also play a significant role for the physiological regulation of the oxytocin-receptor system. Our data indicate that cholesterol acts as an allosteric modulator of the oxytocin receptor and stabilizes both membrane-associated and solubilized OT receptors in a high-affinity state for agonists and antagonists. Moreover, high-affinity OT receptors are 2-fold enriched in cholesterol-rich plasma membrane domains in HEK293 fibroblasts s…
Cloning and Functional Characterization of the Ornithokinin Receptor
1997
Kinins are proinflammatory peptides that dilate vessels, increase vascular permeability, contract smooth muscles, and provoke pain. The known mammalian kinin receptors are classified as two subtypes, i.e. the B1 receptor triggered by [des-Arg9]bradykinin and inhibited by [des-Arg9,Leu8]bradykinin, and the B2 receptor stimulated by bradykinin and antagonized by HOE140. Here we report the cloning of a non-mammalian kinin receptor gene amplified from genomic chicken DNA. The protein predicted from the open reading frame shows 31 and 49% sequence identity to the human B1 and B2 receptors, respectively, suggesting that it represents a G protein-coupled receptor of the kinin receptor family. The …