INIMEC - CONICET   05467
INSTITUTO DE INVESTIGACION MEDICA MERCEDES Y MARTIN FERREYRA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Human platelets Na+/ Ca2+ (NCX) and Na+/Ca2+-K+ (NCKX) exchangers: functional characterization and glycosylation status.
Autor/es:
BISTUÉ MILLÓN, MARÍA BEATRIZ; ELSO BERBERIAN, GRACIELA; ASTEGGIANO, CARLA GABRIELA.
Lugar:
Mendoza
Reunión:
Congreso; Congreso SAIB; 2012
Institución organizadora:
SAIB
Resumen:
Human platelets Na+/
Ca2+ (NCX) and Na+/Ca2+-K+ (NCKX) exchangers: functional
characterization and glycosylation status.
Bistué
Millón, María Beatriz(1); Elso ? Berberian, Graciela(2,4);
Asteggiano, Carla Gabriela(1,3,4)
(1)
Centro de Estudio de las Metabolopatías Congénitas (CEMECO), Facultad de
Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
(2)
Laboratorio Biofísica, Instituto Mercedes y Martín Ferreyra (INIMEC), Córdoba,
Argentina.
(3)
Cátedra Química Biológica, Facultad de Medicina, Universidad Católica de Córdoba,
córdoba, Argentina.
(4)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
*E-mail: asteggianocarla@hotmail.com / *Web
page: www.cdgargentina.com.ar
Congenital
Disorders of Glycosylation (CDG) are human
genetic diseases due to defects in the synthesis of N-, O-glycoproteins,
and even in the synthesis of glycolipids. The clinical features range from a severe
multisystem to mild phenotype. Thrombus-hemorrhagic
events are frequently observed in these patients. In platelets tight
regulation of Ca2+ signaling is necessary to prevent inappropriate
thrombus formation. The Na+/ Ca2+ (NCX) and Na+/Ca2+-K+
(NCKX) exchangers play a crucial
role in controlling cytosolic [Ca2+]. The aim of this work is to contribute to the characterization
of these exchangers in a human megakaryocytic cell line (DAMI cells)
and human platelets. Our results demonstrate (i) the presence
of NCX and the NCKX
proteins in DAMI cells and human platelets by western blot, (ii) that both types of exchangers are functional by measurements of
the Ca2+ (45Ca) uptake, (iii) 2 likely N-glycosylation sites in NCX
protein and different N- and O-glycosylation sites for NCKX1 in the hydrophilic
N-terminal segment by bio-informatics analysis, and (iv) that exchanger proteins are heavily glycosylated by lectin
affinity chromatography and immune-precipitation analysis. Future studies will
elucidate the functional role of glycosylation in the targeting and activity of
NCX and NCKX exchangers in human platelets and CDG patients. CONICET (GI11220090100063) / FONCyT PICT2824.