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Occludin phosphorylation: identification of an occludin kinase in brain and cell extracts as CK2
Author(s) -
Smales Caroline,
Ellis Moira,
Baumber Rachel,
Hussain Nayer,
Desmond Howard,
Staddon James M
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00525-8
Subject(s) - occludin , tight junction , microbiology and biotechnology , phosphorylation , biology , paracellular transport , kinase , biochemistry , chemistry , membrane , permeability (electromagnetism)
In epithelial and endothelial cells, tight junctions limit paracellular flux of ions, proteins and other macromolecules. However, mechanisms regulating tight junction function are not clear. Occludin, a tight junction protein, undergoes phosphorylation changes in several situations but little is known about occludin kinases. A recombinant C‐terminal fragment of occludin is a substrate for a kinase in crude extracts of brain. This activity was purified about 10 000‐fold and identified as CK2 (casein kinase 2) by peptide mass fingerprinting, immunoblotting and mutation of CK2 sites within the occludin sequence. CK2 is therefore a candidate kinase for regulation of occludin phosphorylation in vivo.