STRUCTURE - FUNCTION RELATIONSHIPS OF THE VITAMIN D HORMONE RECEPTOR.

Persistent Link:
http://hdl.handle.net/10150/184182
Title:
STRUCTURE - FUNCTION RELATIONSHIPS OF THE VITAMIN D HORMONE RECEPTOR.
Author:
ALLEGRETTO, ELIZABETH ANNE.
Issue Date:
1987
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Avian intestinal cytosoluble receptors for 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) were subjected to limited trypsin digestion, endogenous proteolytic action, as well as carboxypeptidase treatment, and the physical and functional properties of the resulting discrete polypeptide fragments were identified and contrasted with the native 1,25(OH)₂D₃ receptor. Resultant fragments were followed by tracing either radioactive 1,25(OH)₂D₃ or by probing with anti-receptor monoclonal antibodies. Two differentially trypsin-sensitive effects on the 1,25(OH)₂D₃ receptor were noted when fragments were detected by their ability to bind 1,25(OH)₂[³H]D₃. Two hormone-bound fragments of 40 and 30 kDa were formed; neither bound to DNA-cellulose nor anti-receptor monoclonal antibodies. Immunoblot technology was used to show the disappearance of the 60 kDa receptor with increasing trypsin concentrations, paralleling the appearance of an immunoreactive 20 kDa fragment. The 20 kDa fragment did not bind hormone but was capable of interacting with DNA-cellulose in a fashion identical to that of the 60 kDa receptor. This fragment is likely the complementary fragment to the hormone-bound fragment of 40 kDa that is described above. In contrast to the exogeneous effect of trypsin, incubation of chick intestinal cytosol resulted in the time-dependent formation of an endogenous protease-derived fragment of 45 kDa. This species retained the hormone-binding site and the antibody determinant, but was devoid of DNA-binding activity. Moreover, it did not generate the trypsin-dependent 20 kDa fragment and therefore was derived from the opposite end of the receptor molecule. Carboxypeptidase treatment of the 1,25(OH)₂D₃ receptor produces a 56 kDa fragment which does not retain hormone, but which does bind to DNA-cellulose and monoclonal antibody. These combined data from various limited enzymatic cleavage studies of the receptor have facilitated the construction of a schematic model of the chick receptor in which the immunoreactive epitope is located between the N-terminal DNA-binding domain and the C-terminal hormone-binding domain. This map for the 1,25(OH)₂D₃ receptor protein is consistent with the general structure of steroid and thyroid hormone receptors and places the vitamin D hormone receptor in a class of macromolecules that are postulated to bind enhancer regions of responsive DNA and thereby control target gene transcription.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Vitamin D.; Steroid hormones -- Receptors.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Biochemistry; Graduate College
Degree Grantor:
University of Arizona

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleSTRUCTURE - FUNCTION RELATIONSHIPS OF THE VITAMIN D HORMONE RECEPTOR.en_US
dc.creatorALLEGRETTO, ELIZABETH ANNE.en_US
dc.contributor.authorALLEGRETTO, ELIZABETH ANNE.en_US
dc.date.issued1987en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractAvian intestinal cytosoluble receptors for 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) were subjected to limited trypsin digestion, endogenous proteolytic action, as well as carboxypeptidase treatment, and the physical and functional properties of the resulting discrete polypeptide fragments were identified and contrasted with the native 1,25(OH)₂D₃ receptor. Resultant fragments were followed by tracing either radioactive 1,25(OH)₂D₃ or by probing with anti-receptor monoclonal antibodies. Two differentially trypsin-sensitive effects on the 1,25(OH)₂D₃ receptor were noted when fragments were detected by their ability to bind 1,25(OH)₂[³H]D₃. Two hormone-bound fragments of 40 and 30 kDa were formed; neither bound to DNA-cellulose nor anti-receptor monoclonal antibodies. Immunoblot technology was used to show the disappearance of the 60 kDa receptor with increasing trypsin concentrations, paralleling the appearance of an immunoreactive 20 kDa fragment. The 20 kDa fragment did not bind hormone but was capable of interacting with DNA-cellulose in a fashion identical to that of the 60 kDa receptor. This fragment is likely the complementary fragment to the hormone-bound fragment of 40 kDa that is described above. In contrast to the exogeneous effect of trypsin, incubation of chick intestinal cytosol resulted in the time-dependent formation of an endogenous protease-derived fragment of 45 kDa. This species retained the hormone-binding site and the antibody determinant, but was devoid of DNA-binding activity. Moreover, it did not generate the trypsin-dependent 20 kDa fragment and therefore was derived from the opposite end of the receptor molecule. Carboxypeptidase treatment of the 1,25(OH)₂D₃ receptor produces a 56 kDa fragment which does not retain hormone, but which does bind to DNA-cellulose and monoclonal antibody. These combined data from various limited enzymatic cleavage studies of the receptor have facilitated the construction of a schematic model of the chick receptor in which the immunoreactive epitope is located between the N-terminal DNA-binding domain and the C-terminal hormone-binding domain. This map for the 1,25(OH)₂D₃ receptor protein is consistent with the general structure of steroid and thyroid hormone receptors and places the vitamin D hormone receptor in a class of macromolecules that are postulated to bind enhancer regions of responsive DNA and thereby control target gene transcription.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectVitamin D.en_US
dc.subjectSteroid hormones -- Receptors.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineBiochemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.identifier.proquest8726839en_US
dc.identifier.oclc699805335en_US
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