Growth Arrest and DNA Damage-Inducible Protein GADD34 Assembles a Novel Signaling Complex Containing Protein Phosphatase 1 and Inhibitor 1
Open Access
- 1 October 2001
- journal article
- Published by Informa UK Limited in Molecular and Cellular Biology
- Vol. 21 (20), 6841-6850
- https://doi.org/10.1128/mcb.21.20.6841-6850.2001
Abstract
The growth arrest and DNA damage-inducible protein, GADD34, was identified by its interaction with human inhibitor 1 (I-1), a protein kinase A (PKA)-activated inhibitor of type 1 protein serine/threonine phosphatase (PP1), in a yeast two-hybrid screen of a human brain cDNA library. Recombinant GADD34 (amino acids 233 to 674) bound both PKA-phosphorylated and unphosphorylated I-1(1–171). Serial truncations mapped the C terminus of I-1 (amino acids 142 to 171) as essential for GADD34 binding. In contrast, PKA phosphorylation was required for PP1 binding and inhibition by the N-terminal I-1(1–80) fragment. Pulldowns of GADD34 proteins expressed in HEK293T cells showed that I-1 bound the central domain of GADD34 (amino acids 180 to 483). By comparison, affinity isolation of cellular GADD34/PP1 complexes showed that PP1 bound near the C terminus of GADD34 (amino acids 483 to 619), a region that shows sequence homology with the virulence factors ICP34.5 of herpes simplex virus and NL-S of avian sarcoma virus. While GADD34 inhibited PP1-catalyzed dephosphorylation of phosphorylase a, the GADD34-bound PP1 was an active eIF-2α phosphatase. In brain extracts from active ground squirrels, GADD34 bound both I-1 and PP1 and eIF-2α was largely dephosphorylated. In contrast, the I-1/GADD34 and PP1/GADD34 interactions were disrupted in brain from hibernating animals, in which eIF-2α was highly phosphorylated at serine-51 and protein synthesis was inhibited. These studies suggested that modification of the I-1/GADD34/PP1 signaling complex regulates the initiation of protein translation in mammalian tissues.Keywords
This publication has 75 references indexed in Scilit:
- Ischemia‐Induced Phosphorylation of Initiation Factor 2 in Differentiated PC12 CellsJournal of Neurochemistry, 2000
- Glc7p Protein Phosphatase Inhibits Expression of Glutamine-Fructose-6-phosphate Transaminase from GFA1Published by Elsevier BV ,2000
- The DARPP-32 knockout mouseBrain Research Reviews, 2000
- Interaction between GADD34 and Kinesin Superfamily, KIF3ABiochemical and Biophysical Research Communications, 2000
- The γ134.5 Protein of Herpes Simplex Virus 1 Has the Structural and Functional Attributes of a Protein Phosphatase 1 Regulatory Subunit and Is Present in a High Molecular Weight Complex with the Enzyme in Infected CellsJournal of Biological Chemistry, 1998
- Possible involvement of the novel CPI‐17 protein in protein kinase C signal transduction of rabbit arterial smooth muscleThe Journal of Physiology, 1998
- Conversion of Protein Phosphatase 1 Catalytic Subunit to a Mn2+-Dependent Enzyme Impairs Its Regulation by Inhibitor 1Biochemistry, 1997
- Structural basis for the recognition of regulatory subunits by the catalytic subunit of protein phosphatase 1The EMBO Journal, 1997
- Regulation of protein phosphatase‐1G from rabbit skeletal muscleEuropean Journal of Biochemistry, 1989
- Effect of epinephrine and insulin on the phosphorylation of phosphorylase phosphatase inhibitor 1 in perfused rat skeletal muscleFEBS Letters, 1980