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

      G-Protein Oncogenes in Acromegaly

      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

          G-proteins belong to a family of proteins which share the common properties of GTP binding and hydrolysis. Heterotrimeric G-proteins are composed of α-, β- and γ-subunits. The α-subunit which differs from one G-protein to another contains the GDP/GTP binding site and has intrinsic GTPase activity. The receptor occupancy causes displacement of bound GDP by GTP, dissociation of free βγ-dimer and α-GTP complex, interaction of the activated α-GTP complex with intracellular effectors, such as enzymes and ion channels. The turn off of the reaction is due to the GTPase activity which causes the hydrolysis of GTP to GDP. G-proteins are essential for transferring hormonal signals from cell surface receptors to intracellular effectors. Since G-proteins generate intracellular effectors involved in cell growth, G-protein genes have the propensity to be converted into oncogenes. In fact, mutations in the α-subunit of Gs (the G-protein involved in the activation of adenylyl cyclase) have been demonstrated in 40% of human GH secreting pituitary adenomas. Single amino acid substitutions replacing Arg 201 with either Cys or His or Gin 227 with either Arg or Leu cause constitutive activation of adenylyl cyclase by inhibiting GTPase ( gsp oncogene). The same mutations were identified in about 10% of thyroid adenomas and in the McCune-Albright syndrome.

          Related collections

          Author and article information

          Journal
          HRE
          Horm Res Paediatr
          10.1159/issn.1663-2818
          Hormone Research in Paediatrics
          S. Karger AG
          978-3-8055-5784-9
          978-3-318-01952-0
          1663-2818
          1663-2826
          1992
          1992
          03 December 2008
          : 38
          : 1-2
          : 90-93
          Affiliations
          aInstitute of Endocrine Sciences, Ospedale Maggiore IRCCS and bDepartment of Pharmacology, CNR Center of Cytopharmacology, Scientific Institute San Raffaele, University of Milan, Italy
          Article
          182498 Horm Res 1992;38:90–93
          10.1159/000182498
          1306524
          © 1992 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
          Hormonal Resistance Syndromes

          Comments

          Comment on this article