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SUMOylation does not affect cardiac troponin I stability but alters indirectly the development of force in response to Ca 2+
Author(s) -
Fertig Bracy,
Ling Jiayue,
Nollet Edgar E.,
Dobi Sara,
Busiau Tara,
Ishikawa Kiyotake,
Yamada Kelly,
Lee Ahyoung,
Kho Changwon,
Wills Lauren,
Tibbo Amy J.,
Scott Mark,
Grant Kirsten,
Campbell Kenneth S.,
Birks Emma J.,
MacQuaide Niall,
Hajjar Roger,
Smith Godfrey L.,
Velden Jolanda,
Baillie George S.
Publication year - 2022
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.16537
Subject(s) - sumo protein , myofilament , troponin i , cooperativity , troponin c , biophysics , chemistry , troponin complex , phosphorylation , troponin , microbiology and biotechnology , calcium , biochemistry , medicine , biology , actin , ubiquitin , organic chemistry , myocardial infarction , gene
Post‐translational modification of the myofilament protein troponin I by phosphorylation is known to trigger functional changes that support enhanced contraction and relaxation of the heart. We report for the first time that human troponin I can also be modified by SUMOylation at lysine 177. Functionally, TnI SUMOylation is not a factor in the development of passive and maximal force generation in response to calcium, however this modification seems to act indirectly by preventing SUMOylation of other myofilament proteins to alter calcium sensitivity and cooperativity of myofilaments. Utilising a novel, custom SUMO site‐specific antibody that recognises only the SUMOylated form of troponin I, we verify that this modification occurs in human heart and that it is upregulated during disease.