WAVE1, an A-kinase anchoring protein, during mammalian spermatogenesis.
BACKGROUND
Proper compartmentalization of signalling cascades is paramount to many intracellular activities during spermatogenesis and sperm function. In the present study we focus on the A-kinase-anchoring protein (AKAP) WAVE1, a member of the Wiskott-Aldrich syndrome (WASP) family of adaptor proteins, to study its localization throughout mammalian spermatogenesis.


METHODS
Using transmission electron microscopy, immunocytochemistry and western blotting, we examined the distribution of WAVE1 and putative partners during mammalian spermatogenesis. The localization and association of PKA RII, the regulatory subunit II of protein kinase A, tyrosine kinase Abl, and small GTPase RAC1 were also explored.


RESULTS
WAVE1 localization in spermatocytes and round spermatids coincided with Golgi apparatus distribution, whereas in elongated spermatids and testicular sperm WAVE1 localized to the mitochondrial sheath. Following epididymal passage, WAVE1 was found exclusively on the mitochondrial sheath, suggesting that the protein may function in this region. WAVE1 and PKA RII co-localized along the mitochondrial sheath, PKA RII concentrates in the mid-piece, and RAC1 associated with the post-acrosomal region and the connecting piece. The distribution of WAVE1, PKA RII and RAC1 is conserved in mature mouse, bull, baboon and human sperm.


CONCLUSIONS
The data support the possibility of a functional signalling unit established by WAVE1 and its associated proteins in the mid-piece of maturing sperm.
Pittsburgh Development Center, Magee--Women's Research Institute, Department of Obstetrics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. vanerawe@hotmail.com
Vanesa Y
VY
Rawe
João
J
Ramalho-Santos
Christopher
C
Payne
Hector E
HE
Chemes
Gerald
G
Schatten
D000818:Animals; D002417:Cattle; D002451:Cell Compartmentation; D054754:Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004822:Epididymis / Q000166:cytology / Q000502:physiology; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D008297:Male; D008322:Mammals / Q000502:physiology*; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D010215:Papio; D011506:Proteins / Q000378:metabolism; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism; D051300:Wiskott-Aldrich Syndrome Protein Family; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
D054754:Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit; D008840:Microfilament Proteins; C517819:PRKAR2A protein, human; C517821:Prkar2a protein, mouse; D011506:Proteins; C114864:WASF1 protein, human; C495774:Wasf1 protein, mouse; D051300:Wiskott-Aldrich Syndrome Protein Family; D017868:Cyclic AMP-Dependent Protein Kinases; D020830:rac1 GTP-Binding Protein