Premium
Multiple TSC 22D4 iso‐/phospho‐glycoforms display idiosyncratic subcellular localizations and interacting protein partners
Author(s) -
Canterini Sonia,
Carletti Valentina,
Nusca Stefania,
Mangia Franco,
Fiorenza Maria Teresa
Publication year - 2013
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.12123
Subject(s) - subcellular localization , chemistry , microbiology and biotechnology , biochemistry , biology , gene
Proteins of the TSC22 domain ( TSC22D ) family, including TSC22D1 and TSC22D4 , play pivotal roles in cell proliferation, differentiation and apoptosis, interacting with other factors in a still largely unknown manner. This study explores this issue by biochemically characterizing various TSC22D4 forms (both iso‐ and glyco‐phospho‐, namely the splice variants 42 and 55 kD a and the post‐translationally modified 67 and 72 kD a forms) and their subcellular localization and protein partners during cerebellar granule neuron (CGN) differentiation. The TSC22D4‐42 form is mostly cytosolic, and is the only TSC22D4 form that associates with TSC22D1.2 in undifferentiated but not differentiated CGN s. In contrast, TSC22D4 ‐55 is prominently associated with the nuclear matrix in differentiated but not undifferentiated CGN s. As for TSC22D4‐67 , it is localized in the cytosol and nuclei of undifferentiated CGN s and enters mitochondria of differentiated CGN s, associating with apoptosis‐inducing factor. TSC22D4 ‐72 is modified by O‐linked beta‐N‐acetylglucosamine (O‐GlcNAcylated) and phosphorylated and is always associated with chromatin irrespective of CGN differentiation. The various subcellular localization patterns and interacting protein partners of TSC22D4 forms during CGN differentiation suggest the existence of form‐specific function(s) and provide a novel framework to further investigate the biological functions of TSC22D proteins. Structured digital abstractAIF and TSC22D4 colocalize by cosedimentation ( View interaction ). TSC22D1 physically interacts with TSC22D4 by anti bait coimmunoprecipitation (View Interaction: 1 , 2 ). TSC22D4 physically interacts with AIF by anti bait coimmunoprecipitation (View Interaction: 1 , 2 ). AIF and TSC22D4 colocalize by cosedimentation ( View interaction ).