Characterization of green alga, yeast, and human centrins. Specific subdomain features determine functional diversity.
Centrins are a subfamily within the superfamily of Ca2+-modulated proteins that play a fundamental role in centrosome duplication and contraction of centrin-based fiber systems. We examined the individual molecular properties of yeast, green alga, and human centrins. Circular dichroism spectroscopy revealed a divergent influence of Ca2+ binding on the alpha-helical content of these proteins. Ca2+-free centrins were elongated in shape as determined by size exclusion chromatography. The presence of Ca2+ and binding peptide resulted in more spherical shaped centrins. In contrast to yeast calmodulin, centrins formed multimers in the Ca2+-bound state. This oligomerization was significantly reduced in the absence of Ca2+ and in the presence of binding peptide. The Ca2+-dependent polymerization of the green alga Scherffelia dubia centrin (SdCen) resulted in a filamentous network. This molecular property was mainly dependent on the amino-terminal subdomain and the peptide-binding site of SdCen. Finally, we analyzed whether SdCen and Cdc31p-SdCen hybrid proteins functionally substitute for the Saccharomyces cerevisiae centrin Cdc31p. Only hybrid proteins containing the amino-terminal subdomain or the third EF-hand of SdCen and the other subdomains from Cdc31p were functional in vivo.
Wiech
H
H
Max-Planck-Institut für Biochemie, Genzentrum, Am Klopferspitz 18a, 82152 Martinsried, Federal Republic of Germany.
Geier
B M
BM
Paschke
T
T
Spang
A
A
Grein
K
K
Steinkötter
J
J
Melkonian
M
M
Schiebel
E
E
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D002147:Calmodulin / Q000737:chemistry; D018797:Cell Cycle Proteins / Q000737:chemistry; D000460:Chlorophyta; D002850:Chromatography, Gel; D002868:Chromosomal Proteins, Non-Histone; D002942:Circular Dichroism; D003285:Contractile Proteins / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011485:Protein Binding; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship
C083769:CDC31 protein, S cerevisiae; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D003285:Contractile Proteins; D029701:Saccharomyces cerevisiae Proteins; C056608:caltractin; D002118:Calcium