Artículo
The Spf1p P5A-ATPase “arm-like” domain is not essential for ATP hydrolysis but its deletion impairs autophosphorylation
Grenon, Paula
; Corradi, Gerardo Raul
; Petrovich, Guido Daniel
; Mazzitelli, Luciana Romina
; Adamo, Hugo Pedro
Fecha de publicación:
07/2021
Editorial:
Academic Press Inc Elsevier Science
Revista:
Biochemical and Biophysical Research Communications
ISSN:
0006-291X
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The yeast Spf1p P5A-ATPase actively translocates membrane spanning peptides of mislocalized proteins from the endoplasmic reticulum. Loss of Spf1p function causes a pleiotropic ER stress-phenotype associated with alterations of homeostasis of metal ions, lipids, protein folding, glycosylation, and membrane insertion. A unique characteristic of P5A-ATPases is the presence of an extended insertion which was called the “arm-like” domain connecting the phosphorylation domain (P) with transmembrane segment M5 near the peptidyl-substrate binding pocket. Here we have constructed and characterized a Δarm mutant of Spf1p lacking a segment of 117 amino acids of the “arm-like” domain. The Δarm mutant was capable of hydrolyzing ATP at maximal rates of 50% of that of the wild type enzyme. With the non-nucleotide substrate analog pNPP, the hydrolytic activity of the mutant dropped to 10%. The mutant showed an apparent affinity for ATP similar to the wild type. When incubated with ATP the Δarm mutant produced a lower level of the catalytic phosphoenzyme in amounts proportionate to the ATPase activity. These results indicate that the “arm-like” domain is not essential for hydrolytic activity and suggest that it is needed for the stabilization of Spf1p in a phosphorylation-ready conformation.
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Articulos(IQUIFIB)
Articulos de INST.DE QUIMICA Y FISICO-QUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Articulos de INST.DE QUIMICA Y FISICO-QUIMICA BIOLOGICAS "PROF. ALEJANDRO C. PALADINI"
Citación
Grenon, Paula; Corradi, Gerardo Raul; Petrovich, Guido Daniel; Mazzitelli, Luciana Romina; Adamo, Hugo Pedro; The Spf1p P5A-ATPase “arm-like” domain is not essential for ATP hydrolysis but its deletion impairs autophosphorylation; Academic Press Inc Elsevier Science; Biochemical and Biophysical Research Communications; 563; 7-2021; 113-118
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