Abstract
The structural and functional properties of the aa (2 × 97 kDa) and cc (2 × 94 kDa) isoforms of platelet α‐actinin have been compared. Structural differences between aa and cc are revealed by their peptide maps, obtained from limited proteolysis, and by their immunological cross‐reactivity. Both isoforms stimulate the Mg ATPase activity of actomyosin, bind to F‐actin (high‐speed sedimentation) and cross‐link or gel actin filaments (low‐speed sedimentation and viscometry), in a calcium‐dependent manner. The study of the interaction with F‐actin indicates that the binding of 1 molecule of aa or ccα‐actinin/9‐11 actin monomers is sufficient to produce maximal gelation in the presence of EGTA. CaCl2 at 0.1 mM strongly inhibits the binding of aa to F‐actin and weakly that of cc, while it inhibits similarly the cross‐linking of either aa or cc. The cross‐linking efficiency of cc is 9, 7, 1.7 and 1.3 times higher than that of aa at 4, 20, 30 and 37°C, respectively. The bb form (2 × 96 kDa), which is a proteolytic product of aa [Y. Gache et al. (1984) Biochem. Biophys. Res. Commun. 124, 877‐881], behaves roughly as aa, but the calcium sensitivity of its binding to F‐actin is intermediate between that of aa and cc. These results suggest that the effect of Ca2+ concentration on the binding of platelet α‐actinin to F‐actin may be partly dissociated from the effect on the cross‐linking.
References
34
Referenced
41
10.1016/S0021-9258(17)33023-5
10.1016/0005-2795(67)90544-2
10.1016/0005-2795(70)90173-X
10.1073/pnas.78.5.3005
10.1016/0005-2795(73)90087-1
10.1016/0005-2795(73)90088-3
10.1093/oxfordjournals.jbchem.a134070
10.1016/0167-4838(83)90051-1
10.1111/j.1432-1033.1984.tb08351.x
10.1111/j.1432-1033.1979.tb02054.x
10.1038/294565a0
10.1016/S0021-9258(18)42994-8
10.1016/0167-4838(83)90368-0
10.1111/j.1432-1033.1984.tb08156.x
10.1016/0006-291X(84)91039-8
10.1016/S0021-9258(18)62016-2
10.1016/0022-2836(73)90055-7
10.1016/S0300-9084(82)80472-0
10.1021/bi00806a025
10.1016/0003-2697(74)90367-4
10.1038/227680a0
10.1016/S0021-9258(19)75212-0
10.1073/pnas.76.9.4350
10.1016/S0021-9258(18)84756-1
10.1016/S0021-9258(19)86937-5
10.1083/jcb.85.2.414
10.1073/pnas.74.5.2021
10.1016/0022-2836(72)90464-0
10.1083/jcb.93.3.899
10.1021/bi00303a003
10.1021/bi00316a039
10.1083/jcb.99.1.119s
10.1016/S0021-9258(17)44593-5
10.1002/cm.970020308
Dates
Type | When |
---|---|
Created | 20 years, 5 months ago (March 3, 2005, 7:12 p.m.) |
Deposited | 1 year, 9 months ago (Nov. 23, 2023, 7:12 a.m.) |
Indexed | 1 month, 3 weeks ago (July 8, 2025, 7:30 a.m.) |
Issued | 39 years, 9 months ago (Dec. 1, 1985) |
Published | 39 years, 9 months ago (Dec. 1, 1985) |
Published Online | 20 years, 5 months ago (March 3, 2005) |
Published Print | 39 years, 9 months ago (Dec. 1, 1985) |
@article{LANDON_1985, title={Properties of two isoforms of human blood platelet α‐actinin}, volume={153}, ISSN={1432-1033}, url={http://dx.doi.org/10.1111/j.1432-1033.1985.tb09291.x}, DOI={10.1111/j.1432-1033.1985.tb09291.x}, number={2}, journal={European Journal of Biochemistry}, publisher={Wiley}, author={LANDON, Francoise and GACHE, Yannick and TOUITOU, Hélène and OLOMUCKI, Anna}, year={1985}, month=dec, pages={231–237} }