The protein calsenilin aptamer
Timeline
Dg Jo. et al. found that calsenilin is a protein that interacts with presenilin-2 to cause production of pathogenic Aβ42 in Alzheimer’s disease (AD)[1]
M Osawa et al. found that the protein is active when calcium ion is bound to its EF-hand domain[2]
Theodore A Craig et al. found that active conformation(s) of the protein is modulated by binding of Ca2+[3]
Dong-Gyu Jo et al. found that increased intracellular calcium concentrations favor the active conformation, which induces neuronal apoptosis through interaction with the C-terminus of presenilin-2[4]
Description
In 2007, Lee, K. H. et al.used the SELEX method to isolate the aptamer with high compatibility for the The protein calsenilin. As a functional protein, the biochemical role played by calsenilin may be a consequence of its different conformations. Intrinsically flexible proteins have several energetically degenerate conformations and the active conformation must be induced by binding of a signaling molecule. In the case of calsenilin, calcium ion is the signaling agent[6].SELEX
In 2007, Lee, K. H. et al. carry out a standard SELEX technology using GST-fused calsenilin throughout the whole selection cycle. Since dimeric calsenilin adopts different conformations in the presence and absence of calcium, aptamer selections were independently carried out under both calcium-rich and calcium-free conditions. Selected RNA pools, obtained following 9 cycles of the SELEX procedure in the presence or absence of calcium ion, were cloned and sequenced[6].
Detailed information are accessible on SELEX page.
Structure
The 2D structure of the figure is based on the article by ribodraw tool to draw[6].5'-UUUAUGUAGGGAUGUAAGGGAUGGGCAAUGUGGCGA-3'
Ligand information
SELEX ligand
Recoverin is a Ca(2+) -binding protein that controls phosphorylation of the visual receptor rhodopsin by inhibiting rhodopsin kinase (GRK-1) in photoreceptor cells. It serves as a cancer-retina antigen that is expressed in retina and tumour cells and evokes antibodies and/or T cells in patients with cancer.-----From Pfam
Name | Uniprot ID | Pfam | MW | Amino acids sequences | PDB | Gene ID |
---|---|---|---|---|---|---|
The protein calsenilin | Q9Y2W7 | IPR028846 | 29.24 kDa | MQPAKEVTKASDGSLLGDLGHTPLSKKEGIKWQRPRLSRQALMRCCLVKWILSSTAPQGSDSSDSELELSTVRHQPEGLDQLQAQTKFTKKELQSLYRGFKNECPTGLVDEDTFKLIYAQFFPQGDATTYAHFLFNAFDADGNGAIHFEDFVVGLSILLRGTVHEKLKWAFNLYDINKDGYITKEEMLAIMKSIYDMMGRHTYPILREDAPAEHVERFFEKMDRNQDGVVTIEEFLEACQKDENIMSSMQLFENVI | 2JUL | 30818 |
Some isolated sequences bind to the affinity of the protein.
Name | Sequence | Ligand | Affinity |
---|---|---|---|
aptamer-2 | 5'-GGGACGCGUGGUACCGACGGAGGCUUGUUUAUGUAGGGAUGUAAGGGGAUGGGCAAUGUGGCGACAGCUUCCGCGGGGAUC-3' | The protein calsenilin | 43 nM for Ca2+ bound, 79 nM for Ca2+ unbound |
Similar compound
We used the Dail server website to compare the structural similarities of ligand proteins, and chose the top 10 in terms of similarity for presentation. The Dali server is a network service for comparing protein structures in 3D. Dali compares them against those in the Protein Data Bank (PDB). Z-score is a standard score that is converted from an original score. The list of neighbours is sorted by Z-score. Similarities with a Z-score lower than 2 are spurious. RMSD(Root Mean Square Deviation) value is used to measure the degree to which atoms deviate from the alignment position.
PDB | Z-socre | RMSD | Description |
---|---|---|---|
1S1E-A | 11.5 | 2.1 | KV channel interacting protein 1 |
1FPW-A | 11.0 | 2.3 | Calcium-binding protein ncs-1 |
2R2I-A | 10.9 | 2.1 | Guanylyl cyclase-activating protein 1 |
2GGZ-A | 10.8 | 2.0 | Guanylyl cyclase-activating protein 3 |
2F2P-A | 10.8 | 2.1 | Calmodulin fused with calmodulin-binding domain o |
1H4B-A | 10.0 | 2.3 | Polcalcin bet v 4 |
2N6A-A | 9.9 | 2.2 | Human calmodulin/connexin-36 peptide hybrid |
1V1F-A | 9.7 | 2.5 | Calcineurin b-like protein 4 |
5X9A-B | 9.6 | 2.6 | Calaxin |
4E53-A | 9.6 | 2.2 | Calmodulin, linker, iq motif of neuromodulin |
References
[1] Pro-apoptotic function of calsenilin/DREAM/KChIP3.Jo, D. G., Kim, M. J., Choi, Y. H., Kim, I. K., Song, Y. H., Woo, H. N., Chung, C. W., & Jung, Y. K.
FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 15(3), 589–591. (2001)
[2] Calcium-regulated DNA binding and oligomerization of the neuronal calcium-sensing protein, calsenilin/DREAM/KChIP3.
Osawa, M., Tong, K. I., Lilliehook, C., Wasco, W., Buxbaum, J. D., Cheng, H. Y., Penninger, J. M., Ikura, M., & Ames, J. B.
The Journal of biological chemistry, 276(44), 41005–41013. (2001)
[3] The metal-binding properties of DREAM: evidence for calcium-mediated changes in DREAM structure.
Craig, T. A., Benson, L. M., Venyaminov, S. Y., Klimtchuk, E. S., Bajzer, Z., Prendergast, F. G., Naylor, S., & Kumar, R.
The Journal of biological chemistry, 277(13), 10955–10966. (2002)
[4] Contribution of presenilin/gamma-secretase to calsenilin-mediated apoptosis.
Jo, D. G., Chang, J. W., Hong, H. S., Mook-Jung, I., & Jung, Y. K.
Biochemical and biophysical research communications, 305(1), 62–66. (2003)
[5] Target selectivity in EF-hand calcium binding proteins.
Bhattacharya, S., Bunick, C. G., & Chazin, W. J.
Biochimica et biophysica acta, 1742(1-3), 69–79. (2004)
[6] An RNA aptamer that recognizes a specific conformation of the protein calsenilin.
Lee, K. H., Jeong, S., Yang, E. G., Park, Y. K., & Yu, J.
Bioorganic & medicinal chemistry, 15(24), 7545–7552. (2007)