Rat liver plasma membranes contain FOF1 complexes (ecto-FOF1) displaying a similar molecular weight to the mitochondrial FOF1 ATP synthase, as evidenced by Blue Native PAGE. Their ATPase activity was stably reduced in short-term extra-hepatic cholestasis. Immunoblotting and immunoprecipitation analyses demonstrated that the reduction in activity was not due to a decreased expression of ecto-FOF1 complexes, but to an increased level of an inhibitory protein, ecto-IF1, bound to ecto-F OF1. Since cholestasis down regulates the hepatic uptake of HDL-cholesterol, and ecto-FOF1 has been shown to mediate SR-BI-independent hepatic uptake of HDL-cholesterol, these findings provide support to the hypothesis that ecto-FOF1 contributes to the fine control of reverse cholesterol transport, in parallel with SR-BI. No activity change of the mitochondrial FOF1 ATP synthase (m-F OF1), or any variation of its association with m-IF 1 was observed in cholestasis, indicating that ecto-IF1 expression level is modulated independently from that of ecto-F OF1, m-IF1 and m-FOF1. © Springer Science+Business Media, LLC 2010.
The ectopic FOF1 ATP synthase of rat liver is modulated in acute cholestasis by the inhibitor protein IF1 / Giorgio V.; Bisetto E.; Franca R.; Harris D.A.; Passamonti S.; Lippe G.. - In: JOURNAL OF BIOENERGETICS AND BIOMEMBRANES. - ISSN 0145-479X. - ELETTRONICO. - 42:2(2010), pp. 117-123. [10.1007/s10863-010-9270-2]
The ectopic FOF1 ATP synthase of rat liver is modulated in acute cholestasis by the inhibitor protein IF1
Giorgio V.Primo
;
2010
Abstract
Rat liver plasma membranes contain FOF1 complexes (ecto-FOF1) displaying a similar molecular weight to the mitochondrial FOF1 ATP synthase, as evidenced by Blue Native PAGE. Their ATPase activity was stably reduced in short-term extra-hepatic cholestasis. Immunoblotting and immunoprecipitation analyses demonstrated that the reduction in activity was not due to a decreased expression of ecto-FOF1 complexes, but to an increased level of an inhibitory protein, ecto-IF1, bound to ecto-F OF1. Since cholestasis down regulates the hepatic uptake of HDL-cholesterol, and ecto-FOF1 has been shown to mediate SR-BI-independent hepatic uptake of HDL-cholesterol, these findings provide support to the hypothesis that ecto-FOF1 contributes to the fine control of reverse cholesterol transport, in parallel with SR-BI. No activity change of the mitochondrial FOF1 ATP synthase (m-F OF1), or any variation of its association with m-IF 1 was observed in cholestasis, indicating that ecto-IF1 expression level is modulated independently from that of ecto-F OF1, m-IF1 and m-FOF1. © Springer Science+Business Media, LLC 2010.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.