Biomedical subjects

S M Hollenberg

Publications and source records attributed to S M Hollenberg.

61 records · Page 4Linked to original sources

PubMed1987

Human steroid receptors and erb-A gene products form a superfamily of enhancer-binding proteins.

Steroid hormones exert potent effects on development and differentiation, and their actions are mediated as a consequence of their interaction with specific, high-affinity binding proteins referred to as receptors. To initiate the analysis of the molecular mechanisms by which steroid receptor molecules regulate transcription, we have recently cloned the human glucocorticoid receptor cDNA. The structural analysis of receptor clones reveals 2 protein forms termed 'alpha' and 'beta' which differentiate their carboxy termini. The alpha-receptor is equivalent to the major form of the human glucocorticoid receptor and appears to be the molecule that confers transcriptional control. This protein contains a cysteine-rich region which we believe defines the DNA-binding domain. Structural analysis reveals the receptor to be related to a novel family of proto-oncogenes termed 'erb-A'. To examine this relationship, we have cloned certain members of the erb proto-oncogene family which reveals strong relatedness to the DNA-binding domain of the glucocorticoid receptor. Based on these homologies, we proposed that erb-A protooncogenes are transacting factors that may be candidates for enhancer sequence binding proteins. The unexpected indication from this study is that the steroid receptors and the erb-A proto-oncogenes share a common primordial archetype and therefore appear to be members of new super family of regulatory proteins.

Amino Acid Sequence↗

PubMed1986

Functional domains of the human glucocorticoid receptor.

Human glucocorticoid receptor (hGR) produced in CV-1 cells via transfection of an hGR expression vector functions as a necessary and sufficient factor for the transcriptional activation of the MTV-CAT fusion gene. The magnitude of the induction (500-1000 fold) reveals that the hGR may act as a transcriptional "switch," converting a silent promoter containing a glucocorticoid response element to an activated state. Stimulation of transcription of the MTV-CAT gene fusion by hGR is not dependent on transcriptional factors that are limiting in CV-1 cells. Characterization of 27 insertional mutants of the hGR allowed the location of at least four functional domains, two of which correspond to the predicted DNA- and steroid-binding domains. The other two domains are referred to as tau (tau) for their potent effects on transcription. This raises the possibility that other regions in the receptor are necessary for full transcriptional activation but are not specifically involved in steroid or DNA binding.

Amino Acid Sequence↗

PubMed1985

Primary structure and expression of a functional human glucocorticoid receptor cDNA.

Identification of complementary DNAs encoding the human glucocorticoid receptor predicts two protein forms, of 777 (alpha) and 742 (beta) amino acids, which differ at their carboxy termini. The proteins contain a cysteine/lysine/arginine-rich region which may define the DNA-binding domain. Pure radiolabelled glucocorticoid receptor, synthesized in vitro, is immunoreactive and possesses intrinsic steroid-binding activity characteristic of the native glucocorticoid receptor.

Amino Acid Sequence↗

PubMed1985

Identification of human glucocorticoid receptor complementary DNA clones by epitope selection.

Steroid hormones regulate cellular differentiation and physiologic functions predominantly through gene transcription. Regulation is achieved by the interaction of specific steroid receptor proteins and target genes. Expression cloning techniques were used to select human glucocorticoid receptor complementary DNA clones in order to define the mechanism by which the receptor exerts its transcriptional control. Immobilized fusion proteins from individual clones were used to select epitope-specific antibody which was subsequently eluted and identified by binding to protein blots of cellular extracts. Three cross-hybridizing clones containing inserts expressing antigenic determinants of the human glucocorticoid receptor were isolated.

Cloning, Molecular↗

PubMed1984

Primer-directed mutagenesis of linearized plasmids.

Two novel mutagenesis techniques to specifically alter the sequence of plasmid DNA have been developed. In contrast to other primer-directed mutagenesis methods which require a single-stranded, closed-circular template, a linearized single strand was used as the mutagenesis template. The template is prepared by restriction enzyme digestion of covalently-closed-circular plasmid DNA. These methods are simple, require small amounts of plasmid DNA, and can result in a relatively high frequency of mutagenesis.

Base Sequence↗

PubMed1982

Metabolism of Exogenous Indoleacetic Acid to Its Amide Conjugates in Cucumis sativus L.

Incubation of hypocotyl segments of light-grown Cucumis sativus L. in 0.1 millimolar 3-indoleacetic acid for 16 hours led to the formation of indoleacetylaspartate and indoleacetylglutamate. There was no evidence for the formation of other conjugates of 3-indoleacetic acid with individual amino acids during the period from 4 to 48 hours of incubation. Indoleacetylglutamate reached its maximum concentration after about 4 hours of incubation and indoleacetylaspartate after about 8 hours. These levels remained unchanged for at least 40 hours. Indoleacetylaspartate caused small increases in cucumber hypocotyl segment growth at high concentrations, 1 millimolar being more effective than 0.1 millimolar.

Journal Article↗

PubMedDate not supplied

Domain structure of human glucocorticoid receptor and its relationship to the v-erb-A oncogene product.

The interaction of steroids with their nuclear receptors induces a cascade of regulatory events that results from the activation of specific sets of genes by the hormone/receptor complex. Steroids, either acting alone or possibly synergistically with other growth factors, can influence the DNA synthesis and proliferation of specific target cells, initiate developmental pathways and activate expression of the differentiated phenotype. Moreover, steroid hormones have been implicated in abnormal growth regulation both in tumours and tumour-derived cell lines. The identification of complementary DNAs encoding the human glucocorticoid receptor (hGR) predicts two protein forms (alpha and beta; 777 and 742 amino acids long, respectively) which differ at their carboxy termini. We report here that both forms of the receptor are related, with respect to their domain structure, to the v-erb-A oncogene product of avian erythroblastosis virus (AEV), which suggests that steroid receptor genes and the c-erb-A proto-oncogene are derived from a common primordial regulatory gene. Therefore, oncogenicity by AEV may result, in part, from the inappropriate activity of a truncated steroid receptor or a related regulatory molecule encoded by v-erb-A. This suggests a mechanism by which transacting factors may facilitate transformation. We also identify a short region of hGR that is homologous with the Drosophila homoeotic proteins encoded by Antennapedia and fushi tarazu.

Alpharetrovirus↗