These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Hsp-70 is closely associated with the transferrin receptor in exosomes from maturing reticulocytes.
    Author: Mathew A, Bell A, Johnstone RM.
    Journal: Biochem J; 1995 Jun 15; 308 ( Pt 3)(Pt 3):823-30. PubMed ID: 8948438.
    Abstract:
    The presence of the heat shock protein (hsp-70) has been detected in exocytosed vesicles (which are named exosomes) from mammalian and avian immature red cells (i.e. reticulocytes) as well as from a differentiating avian erythroleukaemic cell line. The close, but non-covalent, association of hsp-70 with the transferrin receptor (TFR) in exosomes is demonstrated by: (1) the ability to cross-link hsp-70 to TFR; (2) the co-immunoprecipitation of hsp-70 and TFR with an antibody against TFR, and the co-immunoprecipitation of TFR and hsp-70 with antibody against hsp-70; and (3) the retention of TFR by hsp-70 bound to ATP-agarose and the simultaneous elution of both proteins by excess ATP. Semi-quantitative analysis of the relative efficiency of cross-linking of these proteins in exosomes versus plasma membranes shows that TFR in exosomes is preferentially bound to hsp-70. From an analysis of the relative amounts of hsp-70 and TFR regenerated from the cross-linked complex, the ratio of TFR monomer bound to hsp-70 is approximately 1.5 to 1. Given the presence of hsp-70 in exosomes from several species and its close association with TFR (the major protein lost during reticulocyte maturation) it is proposed that hsp-70 plays a role in exosome formation and/or release in immature red cells.
    [Abstract] [Full Text] [Related] [New Search]