Abstract
We have used site-directed spin labeling (SDSL) and electron paramagnetic resonance (EPR) to identify residues 17 and 137 as sites of interaction between the head domain and rod domain 1A of the intermediate filament protein vimentin. This interaction was maximal when compared with the spin labels placed at up- and downstream positions in both head and rod regions, indicating that residues 17 and 137 were the closest point of interaction in this region. SDSL EPR characterization of residues 120-145, which includes the site of head contact with rod 1A, reveals that this region exhibits the heptad repeat pattern indicative of α-helical coiled-coil structure, but that this heptad repeat pattern begins to decay near residue 139, suggesting a transition out of coiled-coil structure. By monitoring the spectra of spin labels placed at the 17 and 137 residues during in vitro assembly, we show that 17-137 interaction occurs early in the assembly process. We also explored the effect of phosphorylation on the 17-137 interaction and found that phosphorylation-induced changes affected the head-head interaction (17-17) in the dimer, without significantly influencing the rod-rod (137-137) and head-rod (17-137) interactions in the dimer. These data provide the first direct evidence for, and location of, head-rod interactions in assembled intermediate filaments, as well as direct evidence of coiled-coil structure in rod 1A. Finally, the data identify changes in the structure in this region following in vitro phosphorylation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 7330-7338 |
| Number of pages | 9 |
| Journal | Journal of Biological Chemistry |
| Volume | 284 |
| Issue number | 11 |
| DOIs | |
| State | Published - Mar 13 2009 |
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ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Molecular Biology
Cite this
Head and Rod 1 interactions in Vimentin. Identification of contact sites, structure and changes with phosphorylation using site-directed spin labeling and electron paramagnetic resonance. / Aziz, Atya; Hess, John F.; Budamagunta, Madhu S.; FitzGerald, Paul G; Voss, John C.
In: Journal of Biological Chemistry, Vol. 284, No. 11, 13.03.2009, p. 7330-7338.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Head and Rod 1 interactions in Vimentin. Identification of contact sites, structure and changes with phosphorylation using site-directed spin labeling and electron paramagnetic resonance
AU - Aziz, Atya
AU - Hess, John F.
AU - Budamagunta, Madhu S.
AU - FitzGerald, Paul G
AU - Voss, John C
PY - 2009/3/13
Y1 - 2009/3/13
N2 - We have used site-directed spin labeling (SDSL) and electron paramagnetic resonance (EPR) to identify residues 17 and 137 as sites of interaction between the head domain and rod domain 1A of the intermediate filament protein vimentin. This interaction was maximal when compared with the spin labels placed at up- and downstream positions in both head and rod regions, indicating that residues 17 and 137 were the closest point of interaction in this region. SDSL EPR characterization of residues 120-145, which includes the site of head contact with rod 1A, reveals that this region exhibits the heptad repeat pattern indicative of α-helical coiled-coil structure, but that this heptad repeat pattern begins to decay near residue 139, suggesting a transition out of coiled-coil structure. By monitoring the spectra of spin labels placed at the 17 and 137 residues during in vitro assembly, we show that 17-137 interaction occurs early in the assembly process. We also explored the effect of phosphorylation on the 17-137 interaction and found that phosphorylation-induced changes affected the head-head interaction (17-17) in the dimer, without significantly influencing the rod-rod (137-137) and head-rod (17-137) interactions in the dimer. These data provide the first direct evidence for, and location of, head-rod interactions in assembled intermediate filaments, as well as direct evidence of coiled-coil structure in rod 1A. Finally, the data identify changes in the structure in this region following in vitro phosphorylation.
AB - We have used site-directed spin labeling (SDSL) and electron paramagnetic resonance (EPR) to identify residues 17 and 137 as sites of interaction between the head domain and rod domain 1A of the intermediate filament protein vimentin. This interaction was maximal when compared with the spin labels placed at up- and downstream positions in both head and rod regions, indicating that residues 17 and 137 were the closest point of interaction in this region. SDSL EPR characterization of residues 120-145, which includes the site of head contact with rod 1A, reveals that this region exhibits the heptad repeat pattern indicative of α-helical coiled-coil structure, but that this heptad repeat pattern begins to decay near residue 139, suggesting a transition out of coiled-coil structure. By monitoring the spectra of spin labels placed at the 17 and 137 residues during in vitro assembly, we show that 17-137 interaction occurs early in the assembly process. We also explored the effect of phosphorylation on the 17-137 interaction and found that phosphorylation-induced changes affected the head-head interaction (17-17) in the dimer, without significantly influencing the rod-rod (137-137) and head-rod (17-137) interactions in the dimer. These data provide the first direct evidence for, and location of, head-rod interactions in assembled intermediate filaments, as well as direct evidence of coiled-coil structure in rod 1A. Finally, the data identify changes in the structure in this region following in vitro phosphorylation.
UR - http://www.scopus.com/inward/record.url?scp=65449188330&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=65449188330&partnerID=8YFLogxK
U2 - 10.1074/jbc.M809029200
DO - 10.1074/jbc.M809029200
M3 - Article
C2 - 19117942
AN - SCOPUS:65449188330
VL - 284
SP - 7330
EP - 7338
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 11
ER -