Structures, functions and molecular evolution of the penta-EF-hand Ca2+-binding proteins

Maki, Masatoshi; Kitaura, Yasuyuki; Satoh, Hiroyuki; Ohkouchi, Susumu; Shibata, Hideki

doi:10.1016/s1570-9639(02)00444-2

Cited by 196 publications

(128 citation statements)

References 82 publications

Supporting

Mentioning

126

Contrasting

Order By: Relevance

“…1), binding of a Ca 2þ ion to one loop may allosterically affect the other, both with respect to affinity and binding kinetics (Faas et al 2007;Nelson et al 2002). As a result of this building principle, the majority of EF-hand proteins have an even number of Ca 2þ -binding domains (2 in CB-D9k, 6 in CB-D28k and CR); the uneven number (3) for PV (alpha and beta) is, together with the group of penta-EF-hand Ca 2þ -binding proteins (Maki et al 2002), rather the exception.…”

Section: Metal-binding Affinitiesmentioning

confidence: 99%

Cytosolic Ca2+ Buffers

Schwaller¹

2010

Cold Spring Harbor Perspectives in Biology

350

305

View full text Add to dashboard Cite

Section: Metal-binding Affinitiesmentioning

confidence: 99%

Cytosolic Ca2+ Buffers

Schwaller¹

2010

Cold Spring Harbor Perspectives in Biology

350

305

View full text Add to dashboard Cite

“…However, the overall three-dimensional structures of FCaBP and recoverin are surprisingly quite different and unrelated. Instead, the overall main chain fold of Ca 2ϩ -free FCaBP is most similar to that of apograncalcin (37) and related proteins that belong to the PEF family (50). Interestingly, FCaBP bears very little sequence homology to the PEF proteins (Ͻ20% identity).…”

Section: Surface Properties Of Fcabp-mentioning

confidence: 99%

Structural Insights into Membrane Targeting by the Flagellar Calcium-binding Protein (FCaBP), a Myristoylated and Palmitoylated Calcium Sensor in Trypanosoma cruzi

Wingard

Ladner

Vanarotti

et al. 2008

Journal of Biological Chemistry

View full text Add to dashboard Cite

The flagellar calcium-binding protein (FCaBP) of the protozoan Trypanosoma cruzi is targeted to the flagellar membrane where it regulates flagellar function and assembly. As a first step toward understanding the Ca 2؉ -induced conformational changes important for membrane-targeting, we report here the x-ray crystal structure of FCaBP in the Ca 2؉ -free state determined at 2.2 Å resolution. The first 17 residues from the N terminus appear unstructured and solvent-exposed. Residues implicated in membrane targeting (Lys-19, Lys-22, and Lys-25) are flanked by an exposed N-terminal helix (residues 26 -37), forming a patch of positive charge on the protein surface that may interact electrostatically with flagellar membrane targets. The four EF-hands in FCaBP each adopt a "closed conformation" similar to that seen in Ca 2؉ -free calmodulin. The overall fold of FCaBP is closest to that of grancalcin and other members of the penta EF-hand superfamily. Unlike the dimeric penta EFhand proteins, FCaBP lacks a fifth EF-hand and is monomeric. The unstructured N-terminal region of FCaBP suggests that its covalently attached myristoyl group at the N terminus may be solvent-exposed, in contrast to the highly sequestered myristoyl group seen in recoverin and GCAP1. NMR analysis demonstrates that the myristoyl group attached to FCaBP is indeed solvent-exposed in both the Ca 2؉ -free and Ca 2؉ -bound states, and myristoylation has no effect on protein structure and folding stability. We propose that exposed acyl groups at the N terminus may anchor FCaBP to the flagellar membrane and that Ca 2؉ -induced conformational changes may control its binding to membrane-bound protein targets.Flagellar calcium-binding protein (FCaBP) 3 is a 24-kDa highly immunogenic protein found in the flagellum of the protozoan parasite Trypanosoma cruzi (1). FCaBP contains four EF-hand calcium binding motifs (2, 3) (see Fig. 1), the third and fourth (EF-3 and EF-4) of which bind calcium (4). The protein is modified at the N terminus by covalent attachment of myristate at Gly-2 and palmitate at Cys-4, both of which are required for association with the inner leaflet of the flagellar membrane (5). Calcium is required for stable flagellar localization as well, as FCaBP can be washed out of detergent-permeabilized trypanosomes if calcium chelators are included in the wash solutions. The N-terminal acylation and calcium-dependent membrane localization of FCaBP suggested that the protein may possess a functional calcium-acyl switch, similar to the Ca 2ϩ -myristoyl switch observed previously for recoverin (6, 7) and other members of the neuronal calcium sensor family (8). Acyl switch proteins undergo calcium-dependent membrane association by virtue of calcium-regulated extrusion or sequestration of a myristate moiety that mediates membrane binding (9). However, an FCaBP mutant unable to bind calcium still maintains its flagellar localization, suggesting that FCaBP may not cycle the membrane on and off like some calcium acyl switch proteins (4).The best studied ...

show abstract

“…The small calpain subunit is a member of the penta-EF-hand (PEF) protein family and, within this family, is most similar to sorcin and grancalcin (Maki et al, 2002 hand domain corresponding to domains VI and IV of calpain, and a Pro/Gly-rich N-terminal domain of variable length, corresponding to domain V of calpain. Domain V of calpain is significantly different from the N-terminal extensions of all other PEF proteins because of its outstanding length and peculiar sequence.…”

Section: Lipid-binding Sites Of M-calpain: Roles Of Domain V and The mentioning

confidence: 99%

“…A common feature of non-calpain PEF proteins is their Ca 2q -induced translocation from the cytosol to membranes, where they interact with different target proteins. Depending on the protein targets, Ca 2q -dependent interactions can occur either through the Ca 2q -binding domains or, induced by Ca 2q binding to these domains, through the hydrophobic N-terminal extension (see Maki et al, 2002, for a review). To date, little is known about the interaction of non-calpain PEF proteins with phospholipids, but recently a Ca 2q -dependent increase in hydrophobicity was reported for a PEF protein from maize lacking an N-terminal extension (Barry et al, 2006).…”

Section: Lipid-binding Sites Of M-calpain: Roles Of Domain V and The mentioning

confidence: 99%

μ-Calpain binds to lipid bilayers via the exposed hydrophobic surface of its Ca2+-activated conformation

Fernández-Montalván

Assfalg-Machleidt²,

Pfeiler³

et al. 2006

Biological Chemistry

View full text Add to dashboard Cite

active-site mutated heterodimeric human m-calpain with phospholipid bilayers was studied in vitro using proteinto-lipid fluorescence resonance energy transfer and surface plasmon resonance. Binding to liposomes was Ca 2q -dependent, but not selective for specific phospholipid head groups. wCa 2q x 0.5 for association with lipid bilayers was not lower than that required for the exposure of hydrophobic surface (detected by TNS fluorescence) or for enzyme activity in the absence of lipids. Deletion of domain V reduced the lipid affinity of the isolated small subunit (600-fold) and of the heterodimer (10-to 15-fold), thus confirming the proposed role of domain V for membrane binding. Unexpectedly, mutations in the acidic loop of the 'C2-like' domain III, a putative Ca 2q and phospholipid-binding site, did not affect lipid affinity. Taken together, these results support the hypothesis that in vitro membrane binding of m-calpain is due to the exposed hydrophobic surface of the active conformation and does not reduce the Ca 2q requirement for activation.

show abstract

Structures, functions and molecular evolution of the penta-EF-hand Ca2+-binding proteins

Cited by 196 publications

References 82 publications

Cytosolic Ca2+ Buffers

Cytosolic Ca2+ Buffers

Structural Insights into Membrane Targeting by the Flagellar Calcium-binding Protein (FCaBP), a Myristoylated and Palmitoylated Calcium Sensor in Trypanosoma cruzi

μ-Calpain binds to lipid bilayers via the exposed hydrophobic surface of its Ca2+-activated conformation

Contact Info

Product

Resources

About