Interaction of apoptosis signal-regulating kinase 1 with isoforms of 14-3-3 proteins.
Apoptosis signal-regulating kinase 1 (ASK1) is a critical mediator of apoptotic signaling pathways initiated by a variety of death stimuli. Its activity is tightly controlled by various mechanisms such as covalent modification and protein-protein interaction. One of the proteins that control ASK1 function is 14-3-3zeta, a member of the 14-3-3 protein family. Here, we report that ASK1 is capable of binding to other isoforms of 14-3-3, suggesting that binding ASK1 is a general property of the 14-3-3 family. In support of this notion, mutational analysis revealed that the ASK1/14-3-3 interaction was mediated by the conserved amphipathic groove of 14-3-3 with some residue selectivity. Functionally, expression of various isoforms of 14-3-3 suppressed ASK1-induced apoptosis. To understand how 14-3-3 controls the ASK1 activity, we examined intracellular localization of ASK1 upon 14-3-3 co-expression. We found that 14-3-3 co-expression is correlated with the translocation of ASK1 from the cytoplasm to a perinuclear localization, likely the ER compartment. Consistent with this notion, ASK1(S967A), a 14-3-3 binding defective mutant of ASK, showed no change in intracellular distribution upon 14-3-3 co-expression. These data support a model that 14-3-3 proteins regulate the proapoptotic function of ASK1 in part by controlling its subcellular distribution.
Subramanian
Romesh R
RR
Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA.
Zhang
Hongying
H
Wang
Haining
H
Ichijo
Hidenori
H
Miyashita
Toshiyuki
T
Fu
Haian
H
D048948:14-3-3 Proteins; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D001665:Binding Sites / Q000235:genetics; D019556:COS Cells; D002451:Cell Compartmentation / Q000235:genetics; D004252:DNA Mutational Analysis; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000235:genetics; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics / Q000378:metabolism*
D048948:14-3-3 Proteins; D020033:Protein Isoforms; D014446:Tyrosine 3-Monooxygenase; D048848:MAP Kinase Kinase Kinase 5; D020930:MAP Kinase Kinase Kinases; C482858:MAP3K5 protein, human