Translator Disclaimer
3 January 2014 The Calcium/CaMKKalpha/beta and the cAMP/PKA Pathways Are Essential Upstream Regulators of AMPK Activity in Boar Spermatozoa
Ana Hurtado de Llera, David Martin-Hidalgo, Maria Cruz Gil, Luis J. Garcia-Marin, Maria Julia Bragado
Author Affiliations +
Abstract

Spermatozoa successfully fertilize oocytes depending on cell energy-sensitive processes. We recently showed that the cell energy sensor, the AMP-activated protein kinase (AMPK), plays a relevant role in spermatozoa by regulating motility as well as plasma membrane organization and acrosomal integrity, and contributes to the maintenance of mitochondrial membrane potential. As the signaling pathways that control AMPK activity have been studied exclusively in somatic cells, our aim is to investigate the intracellular pathways that regulate AMPK phosphorylation at Thr172 (activity) in male germ cells. Boar spermatozoa were incubated under different conditions in the presence or absence of Ca2 , 8Br-cAMP, IBMX, PMA, the AMPK activator A769662, or inhibitors of PKA, PKC, or CaMKKalpha/beta. AMPK phosphorylation was evaluated by Western blot using anti-phospho-Thr172-AMPK antibody. Data show that AMPK phosphorylation in spermatozoa is potently stimulated by an elevation of cAMP levels through the activation of PKA, as the PKA inhibitor H89 blocks phospho-Thr172-AMPK. Another mechanism to potently activate AMPK is Ca2 that acts through two pathways, PKA (blocked by H89) and CaMKKalpha/beta (blocked by STO-609). Moreover, phospho-Thr172-AMPK levels greatly increased upon PKC activation induced by PMA, and the PKC inhibitor Ro-32-0432 inhibits TCM-induced AMPK activation. Different stimuli considered as cell stresses (rotenone, cyanide, sorbitol, and complete absence of intracellular Ca2 by BAPTA-AM) also cause AMPK phosphorylation in spermatozoa. In summary, AMPK activity in boar spermatozoa is regulated upstream by different kinases, such as PKA, CaMKKalpha/beta, and PKC, as well as by the essential intracellular messengers for spermatozoan function, Ca2 and cAMP levels.

Ana Hurtado de Llera, David Martin-Hidalgo, Maria Cruz Gil, Luis J. Garcia-Marin, and Maria Julia Bragado "The Calcium/CaMKKalpha/beta and the cAMP/PKA Pathways Are Essential Upstream Regulators of AMPK Activity in Boar Spermatozoa," Biology of Reproduction 90(2), (3 January 2014). https://doi.org/10.1095/biolreprod.113.112797
Received: 2 August 2013; Accepted: 1 December 2013; Published: 3 January 2014
JOURNAL ARTICLE
PAGES

This article is only available to subscribers.
It is not available for individual sale.
+ SAVE TO MY LIBRARY

SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top