title: Decreases in calmodulin binding proteins and calmodulin dependent protein phosphorylation in the medial preoptic area at the onset of maternal behavior in the rat.
abstract: The onset of maternal behavior is characterized by the action of certain hormones, neuropeptides and neurotransmitters and a concomitant increase in the expression of c-Fos in the medial preoptic area (MPOA) but the signaling events that lie between have not been characterized. Because several of these hormones, neuropeptides and neurotransmitters function by activating Ca(2+)/calmodulin (CaM) mediated signaling pathways, many of which can lead to c-Fos expression, the goal of the current work was to identify calmodulin binding proteins (CaMBPs) or specific CaM-dependent phosphoproteins that might be involved. Probing of SDS-PAGE gels of extracts from the hippocampus, parietal cortex, basolateral amygdala and MPOA with recombinant (35)S-VU1-calmodulin (CaM) revealed 30 Ca(2+)-dependent and 4-6 Ca(2+)-independent CaMBPs. Statistically significant maternal behavior-related decreases in four Ca(2+)-dependent CaMBPs ( approximately 31 kDa, 50% decrease; approximately 33 kDa, 32%; approximately 50 kDa, 35%; approximately 60 kDa, 33%) were observed specifically in the MPOA. Numerous proteins were phosphorylated in a Ca(2+) CaM-dependent manner with two (MWs approximately 61 Da, approximately 58 kDa) showing a lack of phosphophorylation only in the MPOA. The selective decrease in CaMBPs coupled with the absence of CaM-dependent phosphoproteins implies that changes in Ca(2+)/CaM-mediated signaling may mediate some of the MPOA-specific processes during the onset of maternal behavior in the rat.
authors.affiliation: Department of Zoology, University of Toronto at Mississauga, Mississauga, Ontario, Canada. doday@credit.erin.utoronto.ca
authors.forename: D H
authors.initials: DH
authors.lastname: O'Day
authors.forename: M
authors.initials: M
authors.lastname: Lydan
authors.forename: J
authors.initials: J
authors.lastname: Watchus
authors.forename: A S
authors.initials: AS
authors.lastname: Fleming
mesh_terms: D000679:Amygdala / Q000378:metabolism; D000818:Animals; D002147:Calmodulin / Q000378:metabolism*; D002148:Calmodulin-Binding Proteins / Q000378:metabolism*; D005260:Female; D006624:Hippocampus / Q000378:metabolism; D008425:Maternal Behavior / Q000502:physiology*; D008969:Molecular Sequence Data; D010296:Parietal Lobe / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D011247:Pregnancy; D011301:Preoptic Area / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction / Q000502:physiology
chemical_list: D002147:Calmodulin; D002148:Calmodulin-Binding Proteins; D010750:Phosphoproteins