Golgi complex disassembly caused by light-activated calphostin C involves MAPK and PKA.
We examined the participation of MAPK and PKA in the Golgi complex disassembly caused by light-activated Calphostin C in HT-29 cells. When these cells were incubated with Calphostin C, fragmentation and dispersal of the Golgi complex was observed as assessed by immunofluorescence microscopy. Electron microscopy analysis showed that clusters of vesicles and large tubule-vesicular membrane structures, resembling the Golgi remnants present in mitotic cells, substituted the Golgi stacks. In addition, Calphostin C treatment caused inhibition of the endocytic route. We confirmed that the Golgi disassembly was not due to PKC inhibition, and suggested, based on the use of specific inhibitors, that other kinases are involved. It was shown that pretreatment with PD98059 and H-89, both inhibitors of MAPK and PKA, respectively, prior to incubation with Calphostin C, caused blockade of the Golgi disassembly, as well as the inhibition of the endocytic pathway caused by this drug. This finding supports the existence of a novel mechanism by which MAPK and PKA may regulate the Golgi breakdown caused by Calphostin C in HT-29 cells.
Morgado-Díaz
J A
JA
Grupo de Biologia Estrutural, Divisão de Biologia Celular, Centro de Pesquisas, Instituto Nacional de Câncer, Rio de Janeiro, RJ 20231-050, Brazil. jmorgado@inca.gov.br
Montesano
G
G
De Souza Fernandes
S
S
Redondo
P A
PA
Fernandes de Souza
W
W
Albuquerque-Xavier
A C
AC
Leve
F
F
Tanaka
M N
MN
Martins de Araujo
W
W
Oliveira
S S
SS
Benchimol
Marlene
M
De Souza
W
W
D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004705:Endocytosis / Q000187:drug effects / Q000528:radiation effects; D005419:Flavonoids / Q000494:pharmacology; D005455:Fluorescent Antibody Technique; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects* / Q000648:ultrastructure; D019073:HT29 Cells; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D008027:Light; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009281:Naphthalenes / Q000737:chemistry / Q000494:pharmacology* / Q000528:radiation effects*; D019311:Staurosporine / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology
D005419:Flavonoids; D007546:Isoquinolines; D009281:Naphthalenes; D013449:Sulfonamides; D006735:Horseradish Peroxidase; D017868:Cyclic AMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D019311:Staurosporine; C058819:calphostin C; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one