RJLs: a new family of Ras-related GTP-binding proteins.
The Ras superfamily of GTP binding proteins encompasses several gene families that regulate a plethora of events in the eukaryotic cell. Here we describe a novel branch of this superfamily which we have named RJLs. These are present in many unicellular organisms and also in deuterostomes but apparently missing in some intermediary phyla, suggesting an intriguing possibility of lateral gene transference between lower and higher eukaryotes. RJLs lack classical membrane targeting signals and the conserved glutamine residue that coordinates GTP hydrolysis in other proteins from the Ras superfamily. Interestingly, chordate orthologues are chimeras fused to "J" domains in their C-terminal, suggesting that these proteins recruit Hsc70 to specific sites in the cell. Expression analysis of RJLs from chordates suggests predominant expression in nervous tissues, possibly reflecting a role for RJLs in the development or maintenance of the sophisticated chordate nervous system.
Nepomuceno-Silva
José L
JL
Instituto de Biofísica Carlos Chagas Filho, Universidades Federal do Rio de Janeiro, Rio de Janeiro, RJ 21949-900, Brazil.
de Melo
Luiz Dione B
LD
Mendonçã
Sergio M
SM
Paixão
Julio C
JC
Lopes
Ulisses G
UG
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D006801:Humans; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics* / Q000502:physiology; D005810:Multigene Family / Q000235:genetics; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014349:Trypanosoma cruzi / Q000235:genetics
D016054:DNA, Protozoan; D020559:Monomeric GTP-Binding Proteins