You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Protein", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Dexamethasone", ...], "Protein" : ["BRCA-1", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Pharmacological characterization of pannexin-1 currents expressed in mammalian cells.
Pannexin (Panx) 1 is a widely expressed protein that shares structural, but not amino acid, homology with gap junction proteins, the connexins. Panx1 does not form gap junctions in mammalian cells, but it may function as a plasma membrane hemichannel. Little is known of the pharmacological properties of panx1 expression in mammalian cells. Here, we identify three variants in the human PANX1 gene. We expressed these variants and mouse Panx1 in mammalian cells and compared Panx1-induced currents. All human Panx1 variants and the mouse Panx1 showed identical protein expression levels, localization patterns, and functional properties, although the frequency of functional expression was species-dependent. Panx1 currents were independent of changes in extracellular or intracellular calcium or phospholipase C transduction. We found compounds that inhibited Panx1 currents with a rank order of potency: carbenoxolone > disodium 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (DIDS) approximately disodium 4-acetamido-4'-isothiocyanato-stilben-2,2'-disulfonate approximately 5-nitro-2-(3-phenylpropylamino)benzoic acid > indanyloxyacetic acid 94 >> probenecid >> flufenamic acid = niflumic acid. Triphosphate nucleotides (ATP, GTP, and UTP) rapidly and reversibly inhibited Panx1 currents via mechanism(s) independent of purine receptors. When Panx1 was coexpressed with purinergic P2X(7) receptor (P2X(7)R), DIDS was found to act as a P2X(7)R antagonist to inhibit ATP-evoked currents, but none of the other compounds inhibited P2X(7)R currents. This is the first detailed pharmacological characterization of Panx1-mediated currents in mammalian cells and sheds new, although contradictory, light on the hypothesis that Panx1 acts as a hemichannel to allow passage of large molecules in response to P2X(7)R activation.
{"Chemical": ["carbenoxolone", "DIDS", "5-nitro-2-(3-phenylpropylamino)benzoic acid", "disodium 4,4\u0027-diisothiocyanatostilbene-2,2\u0027-disulfonate", "GTP", "amino acid", "indanyloxyacetic acid 94", "ATP", "flufenamic acid", "Triphosphate nucleotides", "disodium 4-acetamido-4\u0027-isothiocyanato-stilben-2,2\u0027-disulfonate", "probenecid", "UTP", "niflumic acid"], "Protein": ["purinergic P2X(7) receptor", "human PANX1", "human Panx1", "Panx1", "mouse Panx1", "purine receptors", "plasma membrane hemichannel", "connexins", "panx1", "pannexin-1", "Pannexin (Panx) 1", "P2X(7)R", "phospholipase C"]}