High impact information on ARF2

• We have found a second gene encoding ARF in S. cerevisiae, ARF2 [1].
• Disruption of ARF2 causes no detectable phenotype [1].
• This was not a consequence of reduced PLD catalytic activity, because the enzymatic activity of Spo14 was unaffected in meiotic arf1-myc arf2 mutants [2].
• We have compared the abilities of mammalian ADP-ribosylation factors (ARFs) 1, 5, and 6 and Saccharomyces cerevisiae ARF2 to serve as substrates for the rat liver Golgi membrane guanine nucleotide exchange factor and to initiate the formation of clathrin- and coatomer protein (COP) I-coated vesicles on these membranes [3].
• These ORFs include the genes encoding the large subunit of RNA polymerase II, the biotin apo-protein ligase, an ADP-ribosylation factor (ARF 2), the 'L35'-ribosomal protein, a rho GDP dissociation factor, and the sequence encoding the protein phosphatase 2A [4].

Biological context of ARF2

• Although the two yeast ARF proteins are 96% identical in amino acid sequence, the yeast ARF1 gene is constitutively expressed, whereas the ARF2 gene is repressed by glucose [5].
• The addition of the c-myc epitope at the C terminus of Arf1 resulted in a mutant (arf1-myc arf2) that supported vegetative growth and rescued cells from supersensitivity to fluoride, but homozygous diploids failed to sporulate. arf1-myc arf2 mutants completed both meiotic divisions but were unable to form spores [2].

Other interactions of ARF2

• Spo14 localized normally to the developing prospore membrane in arf1-myc arf2 mutants; however, the synthesis of the membrane was attenuated [2].

References