0
views
0
recommends
+1 Recommend
1 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found

      Growth Hormone- and Prolactin-Binding Proteins: Soluble Forms of Receptors

      Hormone Research in Paediatrics

      S. Karger AG

      GH receptor, Prolactin receptor, Binding proteins, Soluble receptors

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Receptors for growth hormone (GH) and prolactin (PRL) belong to the GH/ PRL/cytokine receptor family, characterized by a unique transmembrane domain and absence of intrinsic tyrosine kinase. The GH receptor (GHR) is a protein of 620 amino acids; the extracellular domain of 246 amino acids is made of two subdomains, one being the domain of interaction with the ligand, the second one being the region of association with another receptor resulting in a homodimer. In addition to the membrane-bound receptor, a soluble form, called the GH-binding protein (GHBP), has been identified in the serum and corresponds to the extracellular domain of the full-length receptor. Two mechanisms of generation for the GHBP exist. In rodents, a 1.2-kb mRNA encodes the GHBP and its hydrophilic C-terminal sequence. In man and many species, no specific mRNA for the GHBP is detected: only one form of mRNA of 4.5 kb encoding the membrane GHR is found by Northern blot analysis. GHBP probably results from proteolytic cleavage of the membrane receptor. Plasma GHBP has a high binding affinity for the hormone comparable to that of the liver GHR. Half-life is longer for GH bound to the binding protein than for free GH. GH-GHBP complex represents a hormone reservoir. Other functions for GHBP remain to be clarified. Plasma levels of GHBP probably reflect the concentration of liver GHRs. Levels of liver GHR and plasma GHBP have been shown to change in parallel. GHBP measurements help in understanding situations of GH resistance. Many factors play a role in the regulation of the plasma GHBP which has been shown to change with age and nutritional status. GH, insulin and sex steroids also influence plasma GHBP levels. No PRL-binding protein has been detected in serum. In rabbit milk a soluble PRL receptor has been identified. The mechanism of its generation and its exact function has to be clarified.

          Related collections

          Author and article information

          Journal
          HRE
          Horm Res Paediatr
          10.1159/issn.1663-2818
          Hormone Research in Paediatrics
          S. Karger AG
          978-3-8055-6290-4
          978-3-318-00047-4
          1663-2818
          1663-2826
          1996
          1996
          09 December 2008
          : 45
          : 3-5
          : 178-181
          Affiliations
          INSERM Unité 344, Endocrinologie Moléculaire, Faculté de Médecine Necker, Paris, France
          Article
          184783 Horm Res 1996;45:178–181
          10.1159/000184783
          8964579
          © 1996 S. Karger AG, Basel

          Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

          Page count
          Pages: 4
          Categories
          Hormone Binding Proteins: Physiology and Clinical Implications

          Comments

          Comment on this article