| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224
Activation-induced cytidine deaminase (AID) is required for somatic hypermutation and class switch recombination of Ig genes in B cells. Although AID has been shown to deaminate deoxycytidine to deoxyuridine in DNA in vitro, there is no physical evidence for increased uracils in DNA from cells expressing AID in vivo. We used several techniques to detect uracil bases in a gene that was actively transcribed in Escherichia coli cells expressing AID. Plasmid DNA containing the gene was digested with uracil-DNA glycosylase to remove uracil, and apurinic/apryimidinic endonuclease to nick the abasic site. The nicked DNA was first analyzed using alkaline gel electrophoresis, in which there was a 2-fold increase in the linear form of the plasmid after AID induction compared with plasmid from noninduced bacteria. Second, using a quantitative denaturing Southern blot technique, the gene was predominantly nicked in the nontranscribed strand compared with the transcribed strand. Third, using ligation-mediated PCR, the nicks were mapped on the nontranscribed strand and were located primarily at cytosine bases. These data present direct evidence for the presence of uracils in DNA from cells that are induced to express AID, and they are preferentially generated at cytosines in the nontranscribed strand during transcription.
This article has been cited by other articles:
|
|
 |
|
  M. Larijani and A. Martin Single-Stranded DNA Structure and Positional Context of the Target Cytidine Determine the Enzymatic Efficiency of AID Mol. Cell. Biol., December 1, 2007; 27(23): 8038 - 8048. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Gomez-Gonzalez and A. Aguilera Activation-induced cytidine deaminase action is strongly stimulated by mutations of the THO complex PNAS, May 15, 2007; 104(20): 8409 - 8414. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Ohm-Laursen and T. Barington Analysis of 6912 Unselected Somatic Hypermutations in Human VDJ Rearrangements Reveals Lack of Strand Specificity and Correlation between Phase II Substitution Rates and Distance to the Nearest 3' Activation-Induced Cytidine Deaminase Target J. Immunol., April 1, 2007; 178(7): 4322 - 4334. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Larijani, A. P. Petrov, O. Kolenchenko, M. Berru, S. N. Krylov, and A. Martin AID Associates with Single-Stranded DNA with High Affinity and a Long Complex Half-Life in a Sequence-Independent Manner Mol. Cell. Biol., January 1, 2007; 27(1): 20 - 30. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
