CIQUIBIC   05472
CENTRO DE INVESTIGACIONES EN QUIMICA BIOLOGICA DE CORDOBA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
IDENTIFICATION OF A MAMMALIAN PALMITOYLTRANSFERASE THAT MODIFIES TRANSMEMBRANE SNARE PROTEINS
Autor/es:
SABRINA CHUMPEN RAMÍREZ ; JAVIER VALDEZ TAUBAS
Lugar:
Puerto Madryn
Reunión:
Congreso; XLVI Reunión Anual- SAIB; 2010
Institución organizadora:
Sociedad Argentina de Investigación Bioquímica y Biología Molecular
Resumen:
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Protein palmitoylation or
S-acylation is a post-translational modification affecting a large number of
proteins. The enzymes responsible for this modification are characterized by
the presence of a DHHC-Cysteine Rich Domain. The yeast S. cerevisiae has 7 members of this family in its genome, and there
are 23 in mammals. Several transmembrane SNAREs, are palmitoylated both in
yeast and mammals. In yeast, this modification is carried out by the Swf1
protein. The mammalian orthologue, has not been identified. Although these
proteins display low conservation outside the DHHC domain, sequence analyses
point to DHHC4 as a putative candidate.
To investigate if DHHC4 is the
enzyme responsible for mammalian SNAREs palmitoylation, we generated a shRNA
against the DHHC4 sequence, to knock-down the protein expression levels in HEK
293 cells. The efficiency of the knock-down was assessed using specific
antibodies against the DHHC4 C-terminus, generated in our laboratory. This
antibodies are also being use to study the intracellular localization of this
protein.
Initially, we used DHHC4 silenced
HEK 293 cells, to assess the palmitoylation status of the yeast SNARE Tlg1. We have
found that Tlg1 palmitoylation is severely reduced in these cells, suggesting
that DHHC4 might indeed be the mammalian SNARE palmitoyltransferase. Several
mammalian SNARES are currently being tested in the same manner.