Identification of the calcium binding sites in translationally controlled tumor protein.
Translationally controlled tumor protein (TCTP), also known as IgE-dependent histamine-releasing factor, is a growth-related tumor protein. Although the primary sequence of rat TCTP does not reveal any recognizable Ca2+ -binding motif, previous studies have demonstrated that rat TCTP consisting of 172 amino acids is a Ca2+ -binding protein. However, the region of TCTP required for Ca2+ interaction has not been mapped to the molecule. Here, we reported that the Ca2+ binding region of TCTP, which was mapped by using a combination of deletion constructs of rat TCTP and 45Ca2+ -overlay assay, was confined to amino acid residues 81-112. This binding domain did not show any peculiar loop of calcium-binding motif such as CaLB domain and EF hand motif and it seems to be constituted of random coil regions neighboring the a helix. Thus, our data confirm that TCTP is a novel family of Ca2+ -binding protein.
Kim
M
M
College of Pharmacy, Center for Cell Signaling Research and Division of Molecular Life Sciences, Ewha Womans University, Seoul, Korea.
Jung
Y
Y
Lee
K
K
Kim
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D014408:Biomarkers, Tumor; D015153:Blotting, Western; D002132:Calcium Radioisotopes; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D017353:Gene Deletion; D018257:Helix-Loop-Helix Motifs; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D017433:Protein Structure, Secondary; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis; D000090324:Tumor Protein, Translationally-Controlled 1
D014408:Biomarkers, Tumor; D002132:Calcium Radioisotopes; D002135:Calcium-Binding Proteins; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; C000715649:Tpt1 protein, rat; D000090324:Tumor Protein, Translationally-Controlled 1; D004247:DNA