title: Characterization of cAMP-dependent proteolysis of GATA-6.
abstract: Cyclic AMP-dependent proteolysis of GATA-6(Delta50) was characterized using inhibitors for intracellular signaling pathways. Among these kinase inhibitors, only H-89 and K252a inhibited the proteolysis induced by dbcAMP, a membrane permeable cAMP analogue, others such as PD98059, SB203580, calphostine C, PP1, and KN-93 did not do so. These results suggest that A-kinase, but not C-kinase, MEK, P38 MAP-kinases or Src kinase, could participate in the observed phenomenon. We further demonstrated that an inhibitor for ubiquitin isopeptidase (Delta12-PGJ2) inhibited the degradation of GATA-6(Delta50) in the presence of dbcAMP, suggesting that the cAMP-dependent proteolysis could be mediated through the ubiquitin-proteasome pathway, although proteasome activity did not change significantly during dbcAMP treatment. The full-length GATA-6 was also responsive to the induced degradation. Furthermore, mutation of a potential phosphorylation site (Ser-290-->Ala) for A- and C-kinases, and deletion of the PEST sequence of GATA-6 did not abolish the degradation. All these results suggest that cellular factor(s) may play a crucial role in mediating the activation of the cAMP-dependent process.
authors.affiliation: Laboratory of Biochemistry and Molecular Biology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Ishida
authors.forename: Ryoko
authors.initials: R
authors.lastname: Iijima
authors.forename: Ayako
authors.initials: A
authors.lastname: Kobayashi
authors.forename: Masatomo
authors.initials: M
authors.lastname: Maeda
mesh_terms: D000818:Animals; D001483:Base Sequence; D001596:Benzylamines / Q000494:pharmacology; D001665:Binding Sites; D003994:Bucladesine / Q000378:metabolism; D016466:CHO Cells; D002227:Carbazoles / Q000494:pharmacology; D002467:Cell Nucleus / Q000378:metabolism; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D050993:GATA6 Transcription Factor; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D026121:Indole Alkaloids; D007546:Isoquinolines / Q000494:pharmacology; D048728:MAP Kinase Kinase Kinase 1 / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008969:Molecular Sequence Data; D009154:Mutation; D009281:Naphthalenes / Q000494:pharmacology; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D015230:Prostaglandin D2 / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D011725:Pyridines / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism; D000096926:Benzenesulfonamides
chemical_list: D001596:Benzylamines; D003994:Bucladesine; D002227:Carbazoles; D000242:Cyclic AMP; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D050993:GATA6 Transcription Factor; D007093:Imidazoles; D026121:Indole Alkaloids; D007546:Isoquinolines; D048728:MAP Kinase Kinase Kinase 1; D009281:Naphthalenes; D015230:Prostaglandin D2; D046988:Proteasome Endopeptidase Complex; D011725:Pyridines; D013449:Sulfonamides; D014157:Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; D019061:src-Family Kinases; C494759:GATA6 protein, human; C499810:delta(12)-prostaglandin J(2); C072105:KN 93; D000096926:Benzenesulfonamides; C049985:staurosporine aglycone; C058819:calphostin C; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one