Published-Ahead-of-Print August 23, 2006, DOI:10.2164/jandrol.106.000182
Journal of Andrology, Vol. 28, No. 1, January/February 2007
Copyright © American Society of Andrology
DOI: 10.2164/jandrol.106.000182
Calcium-Modulated Rod Outer Segment Membrane Guanylate Cyclase Type 1 Transduction Machinery in the Testes
ANNA JANKOWSKA*,
BEATA BURCZYNSKA*,
TERESA DUDA
,
JERZY B. WARCHOL* AND
RAMESHWAR K. SHARMA
From the * Department of Cell Biology, University
of Medical Sciences, Poznan, Poland; and the
Unit of Regulatory and Molecular Biology,
Departments of Cell Biology and Ophthalmology, SOM & NJMS, University of
Medicine and Dentistry of New Jersey, Stratford, New Jersey.
|
Correspondence to: Anna Jankowska, ul. Swiecickiego 6, 60-781 Poznan, Poland
(e-mail:
ajanko{at}amp.edu.pl). |
The importance of the second messengers, Ca2+ and cyclic GMP,
for the process of fertilization is well established; the mechanisms for their
intracellular regulations in the testes are, however, poorly understood. This
study documents the biochemical, molecular, and functional identity of a
Ca2+-modulated membrane guanylate cyclase transduction machinery in
bovine testes. The machinery is both inhibited and stimulated by free
Ca2+ levels. The Ca2+-sensor component of the inhibitory
mode of the machinery is GCAP1 (guanylate cyclase activating protein type 1)
and for the stimulatory mode is S100B. The transduction component is a
Ca2+-driven rod outer segment membrane guanylate cyclase type 1,
ROS-GC1. The cyclase is predominantly expressed in spermatogenic cells. GCAP1
expression is restricted to a small population of spermatogonia, whereas S100B
is present in the majority of spermatocytes and spermatids. The expression of
GCAP1 and S100B in spermatocytes and spermatids is mutually exclusive.
Key words: ROS-GC1, GCAP1, S100B, signal transduction
Copyright © 2007 by The American Society of Andrology.