Identification of the activation-induced cytidine deaminase gene from zebrafish: an evolutionary analysis.
In the present study, we report the identification of the activation-induced cytidine deaminase (AID) encoding gene in frog, dog and chimpanzee, where both somatic hypermutation and class switch recombination (CSR) occurs and in zebrafish and fugu, species lacking CSR. The cDNA sequence of the zebrafish AID reported here suggests both N and C ends of the previously predicted protein sequence are incorrect. A comparison of AID sequences among mammals, birds, amphibians and fish revealed conserved aa residues which may be essential for AID activity, although the cytidine deaminase active motif in the latter is nine amino acids longer. Furthermore, an aa deletion, and extensive substitutions in the C terminal end of AID from bony fish indicate that the molecule may not yet have developed a capacity to recruit the specific cofactor(s) needed to initiate CSR.
Division of Clinical Immunology, Department of Laboratory Medicine, Karolinska Institute at Huddinge Hospital, SE-141 86 Stockholm, Sweden. yaofeng.zhao@labmed.ki.se
Yaofeng
Y
Zhao
Qiang
Q
Pan-Hammarström
Zhihui
Z
Zhao
Lennart
L
Hammarström
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003564:Cytidine Deaminase / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D019143:Evolution, Molecular; D017578:Immunoglobulin Class Switching; D008969:Molecular Sequence Data; D002679:Pan troglodytes; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000235:genetics / Q000378:metabolism*; D000098830:AICDA (Activation-Induced Cytidine Deaminase)
D000098830:AICDA (Activation-Induced Cytidine Deaminase); D003564:Cytidine Deaminase