Isolation and characterization of Leishmania donovani calreticulin gene and its conservation of the RNA binding activity.
Calreticulin has been implicated in multiple cell functions. Recently, we have shown that both human and simian calreticulin are RNA binding proteins and that their binding activity is due to phosphorylation. To demonstrate that the RNA binding property of calreticulin is an intrinsic part of this multi-functional molecule and is evolutionarily conserved, we isolated and characterized the calreticulin gene from the unicellular parasite, Leishmania donovani. Amino acid sequence homology between human and Leishmania calreticulin (L. d. cal) is limited, but like the human homologue, L. d. cal binds Ca+2, can be phosphorylated in vitro and binds certain RNA sequences in a phosphorylation-dependent manner. Unlike human calreticulin, L. d. cal is glycosylated and its binding to endogenous Leishmania RNA is phosphorylation-independent. The binding of L. d. cal to Leishmania RNA suggests that the RNA binding activity of calreticulin has remained evolutionarily conserved.
Joshi
M
M
Laboratory of Molecular Pharmacology, Food and Drug Administration, Bethesda MD 20892-0425, USA.
Pogue
G P
GP
Duncan
R C
RC
Lee
N S
NS
Singh
N K
NK
Atreya
C D
CD
Dwyer
D M
DM
Nakhasi
H L
HL
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D037282:Calreticulin; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D019143:Evolution, Molecular; D017125:Genes, Protozoan; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007893:Leishmania donovani / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D002135:Calcium-Binding Proteins; D037282:Calreticulin; D017931:DNA Primers; D006023:Glycoproteins; D015800:Protozoan Proteins; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins