INBIOMED   24026
INSTITUTO DE INVESTIGACIONES BIOMEDICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The splicing variants of MAP kinase phosphatase-3 (MKP-3) exhibit different properties: impact on ERK-dependent events
Autor/es:
GOROSTIZAGA, ALEJANDRA B; PAZ CRISTINA; MORI SEQUEIROS GARCÍA M MERCEDES; MALOBERTI, PAULA M; COHEN SABBAN JUAN M; NUDLER SILVANA
Lugar:
Mar del Plata
Reunión:
Congreso; LXI Reuniòn Anual de la Sociedad Argentina de Investigación Clínica; 2016
Institución organizadora:
Sociedad Argentina de Investigación Clínica
Resumen:
MAP kinase phosphatase-3 (MKP-3) is an enzyme specific for ERK1/2 and induced exclusively by proliferative stimuli. Two MKP-3 transcripts are expressed in some human cells, a short form (S) and a long form (L), which are products of alternative splicing. The ratio L/S is variable among different tissues and also between normal and tumoral tissues. As MKP-3 S lacks sites that could be involved in the regulation of this enzyme, the aim of this work was to compare the properties of both isoforms. MKP-3 S and L were cloned for the expression of Flag-MKP-3 S or L under a constitutive promoter; then, HEK293 cells were transiently transfected with these vectors. The subcellular localization of each recombinant protein was analyzed by fluorescence microscopy, while P-ERK and flag-MKP-3 S and L levels were evaluated by Western blot using an anti P-ERK or anti-Flag antibody. The results show that MKP-3 S is accumulated equally in the nucleus and cytosol, while MKP-3 L is mainly localized in the cytosol, reflecting the lack of a nuclear export sequence in the S isoform. The levels of P-ERK reached after 15 min of stimulation with fetal bovine serum (FBS) were lower in cells transfected with either isoform, which indicates that these expression products are active. In addition, the isoforms presented differences in post-translational regulation, as similar levels of flag-MKP-3 L were detected after different times of FBS stimulation, whereas isoform S was accumulated over the same period (4.5-fold at 90 minutes, P