Liver enriched transcription factor

• US 6,500,672 B1
• Filed: 11/22/1999
• Issued: 12/31/2002
• Est. Priority Date: 12/21/1990
• Status: Expired due to Fees

• Current Assignee: Rockefeller University
• Original Assignee: Rockefeller University
• Inventors: Sladek, Frances M., Zhong, Weimin, Darnell, James E. Jr.
• Primary Examiner(s): Prouty, Rebecca E.
• Assistant Examiner(s): Rao, Manjunath N.
• Application Number:
  US09/447,034
• Time in Patent Office: 1,135 Days
• Field of Search: 530/350, 530/358, 530/361, 530/387-3, 530/388.21, 530/387.9, 536/23-2, 436/501, 436/86
• US Class Current: 436/501
• CPC Class Codes: A61K 38/00 Medicinal preparations containing peptides peptides containing beta-lactam rings A61K31/00; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, A61K31/00; ergot alkaloids of the cyclic peptide type A61K31/48; containing macromolecular compounds having statistically distributed amino acid units A61K31/74; medicinal preparations containing antigens or antibodies A61K39/00; medicinal preparations characterised by the non-active ingredients, e.g. peptides as drug carriers, A61K47/00
• CPC Class Codes: A61P 3/04 Anorexiants; Antiobesity agents
• CPC Class Codes: A61P 9/00 Drugs for disorders of the cardiovascular system
• CPC Class Codes: C07K 14/47 from mammals
• CPC Class Codes: C07K 14/4702 Regulators; Modulating activity
• CPC Class Codes: C07K 14/70571 for neuromediators, e.g. serotonin receptor, dopamine receptor
• CPC Class Codes: C07K 14/721 Steroid/thyroid hormone superfamily, e.g. GR, EcR, androgen receptor, oestrogen receptor
• CPC Class Codes: C07K 16/4258 against anti-receptor Ig
• CPC Class Codes: C07K 2319/00 Fusion polypeptide
• CPC Class Codes: C07K 2319/30 Non-immunoglobulin-derived peptide or protein having an immunoglobulin constant or Fc region, or a fragment thereof, attached thereto
• CPC Class Codes: C07K 2319/81 containing a Zn-finger domain for DNA binding
• CPC Class Codes: C12N 15/113 Non-coding nucleic acids modulating the expression of genes, e.g. antisense oligonucleotides; Antisense DNA or RNA; Triplex- forming oligonucleotides; Catalytic nucleic acids, e.g. ribozymes; Nucleic acids used in co-suppression or gene silencing when used in plants C12N15/8218
• CPC Class Codes: C12N 15/67 General methods for enhancing the expression
• CPC Class Codes: G01N 33/534 with radioactive label

Abstract

HNF-4 (hepatocyte nuclear factor 4) is a protein enriched in liver extracts that binds to sites required for the transcription of the transthyretin (TTR) and apolipoprotein CIII (apoCIII) genes (Costa et al., 1989; Costa et al., 1990; Leff et al., 1989). We have purified HNF-4 protein (54 kD) and isolated a cDNA clone encoding the protein. HNF-4 is a member of the steroid hormone receptor superfamily with an unusual amino acid in the conserved “knuckle” of the first zinc finger (DGCKG). This and the fact that HNF-4 does not bind significantly to estrogen, thyroid hormone or glucocorticoid response elements indicate that HNF-4 may represent a new subfamily. HNF-4 binds to its recognition site as a dimer and activates transcription in a sequence-specific fashion in nonhepatic (HeLa) cells. HNF-4 mRNA is present in kidney and intestine as well as liver but is absent in other tissues. DNA binding data suggest that HNF-4 could be identical to liver factor A1 (LF-A1), a factor previously shown to regulate the transcription of the α-1 antitrypsin, apolipoprotein A1 and pyruvate kinase genes.

Claims

1. A competitive assay for binding activity to recombinant HNF-4 receptors, comprising:

(a) reacting a suspected ligand with a recombinant HNF-4 receptor in the presence of a known quantity of a labeled competing ligand; and

(b) comparing the amount of bound label in the presence of the suspected ligand to that observed in its absence, wherein the HNF-4 receptor is a chimeric receptor comprising the ligand binding domain of a HNF-4 receptor and a DNA binding domain of another receptor which has a known ligand.

2. The assay of claim 1, wherein the DNA binding domain is from a glucocorticoid receptor.

3. The assay of claim 1, wherein the DNA binding domain is from an estrogen receptor.

4. The assay of claim 1, wherein the DNA binding domain is from a retinoic acid receptor.

5. The assay of claim 1, wherein the HNF-4 receptor is a chimeric receptor comprising a fragment of the ligand binding domain of the HNF-4 receptor, and the DNA binding domain of another receptor which has a known ligand, and wherein the fragment of the ligand binding domain retains ligand binding activity.