title: CacyBP/SIP, a calcyclin and Siah-1-interacting protein, binds EF-hand proteins of the S100 family.
abstract: Recently, a human ortholog of mouse calcyclin (S100A6)-binding protein (CacyBP) called SIP (Siah-1-interacting protein) was shown to be a component of a novel ubiquitinylation pathway regulating beta-catenin degradation (Matsuzawa, S., and Reed, J. C. (2001) Mol. Cell 7, 915-926). In murine brain, CacyBP/SIP is expressed at a high level, but S100A6 is expressed at a very low level. Consequently we carried out experiments to determine if CacyBP/SIP binds to other S100 proteins in this tissue. Using CacyBP/SIP affinity chromatography, we found that S100B from the brain extract binds to CacyBP/SIP in a Ca2+-dependent manner. Using a nitrocellulose overlay assay with 125I-CacyBP/SIP and CacyBP/SIP affinity chromatography, we found that this protein binds purified S100A1, S100A6, S100A12, S100B, and S100P but not S100A4, calbindin D(9k), parvalbumin, and calmodulin. The interaction of S100 proteins with CacyBP/SIP occurs via its C-terminal fragment (residues 155-229). Co-immunoprecipitation of CacyBP/SIP with S100B from brain and with S100A6 from Ehrlich ascites tumor cells suggests that these interactions are physiologically relevant and that the ubiquitinylation complex involving CacyBP/SIP might be regulated by S100 proteins.
authors.affiliation: Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland. anfil@nencki.gov.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Filipek
authors.forename: Beata
authors.initials: B
authors.lastname: Jastrzebska
authors.forename: Marcin
authors.initials: M
authors.lastname: Nowotny
authors.forename: Jacek
authors.initials: J
authors.lastname: Kuznicki
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D018797:Cell Cycle Proteins; D002846:Chromatography, Affinity; D020832:EF Hand Motifs; D004591:Electrophoresis, Polyacrylamide Gel; D006639:Histidine / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D009414:Nerve Growth Factors / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D000075383:S100 Calcium Binding Protein A6; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D025801:Ubiquitin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases; D000098563:Seven in Absentia Proteins
chemical_list: C491778:CACYBP protein, human; C491777:CacyBP protein, rat; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; D009414:Nerve Growth Factors; D009687:Nuclear Proteins; D000075383:S100 Calcium Binding Protein A6; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C110294:S100A1 protein; C579160:S100B protein, human; C489134:S100a6 protein, mouse; C489132:S100a6 protein, rat; C579159:S100b protein, mouse; C579158:S100b protein, rat; D025801:Ubiquitin; D006639:Histidine; D044767:Ubiquitin-Protein Ligases; D000098563:Seven in Absentia Proteins