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V‐ATPase/small GTPase/aldolase complex and regulation of endosomal/lysosomal protein degradative pathway
Author(s) -
Merkulova Maria,
HurtadoLorenzo Andres,
Brown Dennis,
Ausiello Dennis,
Marshansky Vladimir
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.877.4
Subject(s) - aldolase a , endosome , microbiology and biotechnology , atpase , biochemistry , gtpase , chemistry , small gtpase , enzyme , fructose bisphosphate aldolase , biology , signal transduction , cell
V‐ATPase‐driven acidification is crucial for regulation of endosomal/lysosomal protein degradative pathway. Recently we demonstrated that the V‐ATPase has a novel function as endosomal pH‐sensor which scaffolds ARNO and Arf6 small GTPases. Using the combination of pull‐down experiments and mass‐spectrometry analysis, here we demonstrated that ARNO's protein‐protein interaction network also includes: i) a1‐, a3‐ and a4‐isoforms of V‐ATPase; ii) enzymes of glycolytic pathway, iii) adaptors; iv) coats and v) cytoskeletal proteins. Immunoprecipitation experiments demonstrated that ARNO specifically interacts with aldolase, but not with other enzymes of glycolytic pathway. The direct interaction of aldolase with ARNO was further confirmed in pull‐down experiments with recombinant proteins. Moreover, additional experiments demonstrated that specific interaction of aldolase with ARNO is taking place via its PH‐domain. Thus using the combination of proteomic approaches we uncover the direct interaction of ARNO with aldolase, the crucial enzyme of glycolytic pathway and modulator of V‐ATPase. Our data indicate on novel regulatory role of ARNO in function of aldolase and potentially in assembly/disassembly of V‐ATPase. The cell biological significance of the interaction between V‐ATPase, ARNO and aldolase in regulation of endosomal/lysosomal protein degradative pathway is further discussed.