@article{TEXTUAL,
      recid = {10397},
      author = {Bright, Lydia J. and Kambesis, Nichole and Nelson, Scott  Brent and Jeong, Byeongmoon and Turkewitz, Aaron P.},
      title = {Comprehensive Analysis Reveals Dynamic and Evolutionary  Plasticity of Rab GTPases and Membrane Traffic in  <i>Tetrahymena thermophila</i>},
      journal = {PLOS Genetics},
      address = {2010-10-14},
      number = {TEXTUAL},
      abstract = {<p>Cellular sophistication is not exclusive to  multicellular organisms, and unicellular eukaryotes can  resemble differentiated animal cells in their complex  network of membrane-bound structures. These comparisons can  be illuminated by genome-wide surveys of key gene families.  We report a systematic analysis of Rabs in a complex  unicellular Ciliate, including gene prediction and  phylogenetic clustering, expression profiling based on  public data, and Green Fluorescent Protein (GFP) tagging.  Rabs are monomeric GTPases that regulate membrane traffic.  Because Rabs act as compartment-specific determinants, the  number of Rabs in an organism reflects intracellular  complexity. The <em>Tetrahymena</em> Rab family is similar  in size to that in humans and includes both expansions in  conserved Rab clades as well as many divergent Rabs.  Importantly, more than 90% of Rabs are expressed  concurrently in growing cells, while only a small subset  appears specialized for other conditions. By localizing  most Rabs in living cells, we could assign the majority to  specific compartments. These results validated most  phylogenetic assignments, but also indicated that some  sequence-conserved Rabs were co-opted for novel functions.  Our survey uncovered a rare example of a nuclear Rab and  substantiated the existence of a previously unrecognized  core Rab clade in eukaryotes. Strikingly, several  functionally conserved pathways or structures were found to  be associated entirely with divergent Rabs. These pathways  may have permitted rapid evolution of the associated Rabs  or may have arisen independently in diverse lineages and  then converged. Thus, characterizing entire gene families  can provide insight into the evolutionary flexibility of  fundamental cellular pathways.</p>},
      url = {http://knowledge.uchicago.edu/record/10397},
}