The Ca2+-binding proteins parvalbumin and oncomodulin and their genes: new structural and functional findings

Reactive oxygen species modulate the differentiation of neurons in clonal cortical cultures

“…The firing properties observed for the type I neurons appear to be consistent with those reported in the developing rat cortex in immature pyramidal cells (Luhmann et al, 2003) and in young migratory neurons (Noctor et al, 2004). Type I and type II neurons also differed in their expression of calretinin, a Ca 2+ binding protein (CaBP) that is believed to buffer intracellular Ca 2+ (Heizmann, 1984), contribute to membrane repolarization (Pauls et al, 1996), and modulate calcium-signaling (Hubbard and McHugh, 1995). In addition, calretinin is a marker for subpopulations of cortical GABAergic interneurons (del Rio and DeFelipe, 1997; Kubota et al, 1994;Xu et al, 2003) and is found in non-GABAergic neurons of the cortical plate, including Cajal-Retzius cells (del Rio et al, 1995;Weisenhorn et al, 1994).…”

Resurrecting prehistoric parvalbumins to explore the evolution of thermal compensation in extant Antarctic fish parvalbumins

“…The Ca 2+ coordinating residues are contained in a conserved 12 residue loop at relative positions 1, 3, 5, 7, 9 and 12 that correspond to a coordinate system: X, -X, Y, -Y, Z, -Z binding in a pentagonal bipyramidal arrangement (Fig.1B,C) (Lewit-Bentley and Réty, 2000). The ion-binding domains, CD and EF, are highly conserved (Pauls et al, 1996) while the AB domain has a much more variable sequence and is considered to be the remnant of an ancestral binding site that has lost ion-binding function due to the loss of its paired EF-hand and two residues in its loop region (Cox et al, 1999).…”

Binding of calcium ions and SNAP-25 to the hexa EF-hand protein secretagogin

“…Many EF-hand proteins belong to one of two classes: (i) signalling proteins or (ii) buffering proteins. EF-hand proteins that function as Ca 2+ -buffers or transporters have high Ca 2+ affinities (K d < 0.1 µM) and undergo only minor conformational changes upon binding of Ca 2+ (for a review, see [12]). An important biological function of Ca 2+ -buffer proteins is to maintain nontoxic levels of free intracellular Ca 2+ and to restore the low resting level after signalling events.…”