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Ubiquitination of red blood cell α‐spectrin does not affect heterodimer formation
Author(s) -
Riahi Mahnoush H.,
Kakhniashvili David G.,
Goodman Steven R.
Publication year - 2005
Publication title -
american journal of hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.456
H-Index - 105
eISSN - 1096-8652
pISSN - 0361-8609
DOI - 10.1002/ajh.20282
Subject(s) - spectrin , epb41 , ubiquitin , protein subunit , immunoprecipitation , chemistry , red blood cell , microbiology and biotechnology , biophysics , biochemistry , biology , cell , cytoskeleton , gene
Erythrocyte α‐spectrin is ubiquitinated in repeats α20/α21, which also represents the nucleation site for contact with the β subunit which leads to heterodimer formation by a zippering mechanism. In this study we have determined the second‐order rate constant for association of ubiquitinated α′‐spectrin, nonubiquitinated α‐spectrin, and β‐spectrin into the α′β or αβ heterodimer. The rate constant for incorporation of monomers into heterodimers at 37°C were (5.181 ± 0.001) × 10 5 M −1 sec −1 for total α‐spectrin (α + α′), (5.121 ± 0.001) × 10 5 M −1 sec −1 for α′‐spectrin, and (5.178 ± 0.003) × 10 5 M −1 sec −1 for β‐spectrin. We conclude that ubiquitination of α‐spectrin does not regulate heterodimer formation. Am. J. Hematol. 78:281–287, 2005. © 2005 Wiley‐Liss, Inc.