HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Leibovitz, D. Articles by Amsterdam, A. Search for Related Content PubMed PubMed Citation Articles by Leibovitz, D. Articles by Amsterdam, A. Social Bookmarking                      What's this?

JBC, Vol. 270, Issue 19, 11029-11032, May, 1995

Archaebacterial and eukaryotic proteasomes prefer different sites in cleaving gonadotropin-releasing hormone

D Leibovitz, Y Koch, M Fridkin, F Pitzer, P Zwickl, A Dantes, W Baumeister and A Amsterdam
Department of Hormone Research, Weizmann Institute of Science, Rehovot, Israel.

Thermoplasma 20 S proteasomes are composed of only two different types of subunits (designated as alpha and beta) but are nearly indistinguishable in their quaternary structure from eukaryotic 20 S proteasomes consisting of 14 distinct subunits. In this study, we compared both the nature and the rate of the proteolytic activities of Thermoplasma and of granulosa cell proteasomes on the neurohormone, gonadotropin-releasing hormone (GnRH), the degradation products of which can be unequivocally identified. Both Thermoplasma and granulosa proteasome degrade the decapeptide GnRH at the Trp3-Ser4, Ser4-Tyr5, Tyr5-Gly6, and Gly6-Leu7 bonds. While the main product of Thermoplasma proteasomes was a GnRH-(1-4) fragment, the main product of granulosa cell proteasome was a GnRH-(1-5) fragment, indicating that the principal degrading activity of Thermoplasma proteasome targets Ser4- Tyr5 bond, while the principal degrading activity of granulosa cell proteasome targets the Tyr5-Gly6 bond of GnRH. These differences in the degradation pattern of the neurohormone were observed when proteasome activities were compared both at 60 degrees C, the optimal temperature for Thermoplasma proteasomal activity, and at 37 degrees C, the optimal temperature of granulosa proteasome proteolytic activity. Although the catalytic mechanism is probably conserved from archaebacterial to eukaryotic proteasomes, our results suggest that there are striking differences in the preferred cleavage site of GnRH. This reflects the changes in the proteasomal subunit repertoire during evolution.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				T.A. Bramley and G.S. Menzies Human placental gonadotrophin-releasing hormone-like factors: an artefact of human placental peptidases? Mol. Hum. Reprod., February 1, 2000; 6(2): 113 - 126. [Abstract] [Full Text] [PDF]

				A. J. L. Macario, M. Lange, B. K. Ahring, and E. C. De Macario Stress Genes and Proteins in the Archaea Microbiol. Mol. Biol. Rev., December 1, 1999; 63(4): 923 - 967. [Abstract] [Full Text] [PDF]

				A. F. Kisselev, T. N. Akopian, K. M. Woo, and A. L. Goldberg The Sizes of Peptides Generated from Protein by Mammalian 26 and 20 S Proteasomes. IMPLICATIONS FOR UNDERSTANDING THE DEGRADATIVE MECHANISM AND ANTIGEN PRESENTATION J. Biol. Chem., February 5, 1999; 274(6): 3363 - 3371. [Abstract] [Full Text] [PDF]

				A. Amsterdam and N. Selvaraj Control of Differentiation, Transformation, and Apoptosis in Granulosa Cells by Oncogenes, Oncoviruses, and Tumor Suppressor Genes Endocr. Rev., August 1, 1997; 18(4): 435 - 461. [Abstract] [Full Text] [PDF]

				G. Niedermann, R. Grimm, E. Geier, M. Maurer, C. Realini, C. Gartmann, J. Soll, S. Omura, M. C. Rechsteiner, W. Baumeister, et al. Potential Immunocompetence of Proteolytic Fragments Produced by Proteasomes before Evolution of the Vertebrate Immune System J. Exp. Med., July 21, 1997; 186(2): 209 - 220. [Abstract] [Full Text] [PDF]