PROTEOMIC ANALYSIS OF MUTANT CELL CULTURES FOR TWO MITCHONDRIAL CARBONIC ANHYDRASES LIKE GENES

VILLARREAL FERNANDO; MARTÍN VICTORIA; SCHROTT GERMÁN; ZABALETA EDUARDO

Carlos Paz, Cordoba, Argentina

Congreso; XLIV Reunión anual de la Sociedad Argentina de investigación Bioquímica y Biología Molecular (SAIB).; 2008

Sociedad Argentina de de investigación Bioquímica y Biología Molecular (SAIB)

The gene family of putative gamma-class Carbonic Anhydrases in Arabidopsis genomeincludes five members. Three of these genes (CA1, CA2 and CA3), share higherhomology with the highly characterized gamma-CAs from the archea M. thermophila,and two CA-Like genes (CAL1 and CAL2) show a minor degree of homology. Bybioinformatic analysis, the CALs proteins lacks a number of aminoacid important tocreate the functional active site of the mature homotrimer, but they can form part of amature heterotrimer together with two CA subunits. The five CA and CAL proteins arelocated into mitochondria and bounded to mitochondrial Complex I, forming an extradomain exclusive of photosyntetic organisms. By proteomics analysis, we showed thatca2 mutant cell culture exhibited a 80% reduction in Complex I levels, but this featurewas not observed in ca1 or ca3 mutants. In this work, we analized the mitochondrialproteome of cal1 mutant and cal1cal2 mutant cell cultures (despite all efforts, we werenot able to obtain cal2 cell cultures). We observed that cal1 and cal1cal2 cell culturespresented normal amounts of all mitochondrial complexes. A detailed analysis showedthat both mutants lacked the same two bands in silver stained 2D BN-SDS gels andonly one band in western blots. This suggested an epistatic relationship between CAL1and CAL2, but this needs further investigation.