title: Pharmacological analysis of CCK2 receptors up-regulated using engineered transcription factors.
abstract: Designed zinc finger proteins (ZFPs) regulate expression of target genes when coupled to activator or repressor domains. Transfection of ZFPs into cell lines can create expression systems where the targeted endogenous gene is transcribed and the protein of interest can be investigated in its own cellular context. Here we describe the pharmacological investigation of an expression system generated using CCK2 receptor-selective ZFPs transfected into human embryonic kidney cells (HEKZFP system). The receptors expressed in this system, in response to ZFP expression, were functional in calcium mobilization studies and the potency of the agonists investigated was consistent with their action at CCK2 receptors (CCK-8S pA50 = 9.05+/-0.11, pentagastrin pA50 = 9.11+/-0.13). In addition, binding studies were conducted using [125I]-BH-CCK-8S as radioligand. The saturation binding analysis of this radioligand was consistent with a single population of high affinity CCK receptors (pK(D) = 10.24). Competition studies were also conducted using a number of previously well-characterized CCK-receptor selective ligands; JB93182, YF476, PD-134,308, SR27897, dexloxiglumide, L-365,260 and L-364,718. Overall, the estimated affinity values for these ligands were consistent with their interaction at CCK2 receptors. Therefore, CCK2 receptors up-regulated using zinc finger protein technology can provide an alternative to standard transfection techniques for the pharmacological analysis of compounds.
authors.affiliation: Johnson & Johnson Pharmaceutical Research & Development, LLC., 3210 Merryfield Row, San Diego, CA, 92121, USA. mmorton1@prdus.jnj.com
authors.forename: Magda F
authors.initials: MF
authors.lastname: Morton
authors.forename: Pei-Qi
authors.initials: PQ
authors.lastname: Liu
authors.forename: Andreas
authors.initials: A
authors.lastname: Reik
authors.forename: Ragan
authors.initials: R
authors.lastname: de la Rosa
authors.forename: Matthew
authors.initials: M
authors.lastname: Mendel
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Li
authors.forename: Casey
authors.initials: C
authors.lastname: Case
authors.forename: Carl
authors.initials: C
authors.lastname: Pabo
authors.forename: Veronica
authors.initials: V
authors.lastname: Moreno
authors.forename: Jayashree
authors.initials: J
authors.lastname: Pyati
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Shankley
mesh_terms: D002460:Cell Line; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006801:Humans; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D008024:Ligands; D004364:Pharmaceutical Preparations / Q000378:metabolism; D043887:Receptor, Cholecystokinin B / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation / Q000187:drug effects* / Q000235:genetics; D016335:Zinc Fingers / Q000235:genetics / Q000502:physiology
chemical_list: D008024:Ligands; D004364:Pharmaceutical Preparations; D043887:Receptor, Cholecystokinin B; D014157:Transcription Factors