Organization of a human UDP-GalNAc:polypeptide, N-acetylgalactosaminyltransferase gene and a related processed pseudogene.
We have previously characterized a cDNA that encodes a full length human UDP-GalNAc:polypeptide, N-acetylgalactosaminyltransferase (GalNAc-transferase) (J.A. Meurer et al., J. Biochem., 118, 568-574, 1995). The present report describes the characterization of the corresponding human GalNAc-transferase gene and a related pseudogene. Two human genomic libraries, lambda and P1, were screened with probes derived from the human GalNAc-transferase nucleotide sequence, resulting in the isolation of four genomic clones. Southern blotting, PCR analysis, and sequencing revealed that three clones, lambda.HG-5, P1.GALN-A, and P1.GALN-B, contained overlapping genomic sequences that encompass over 55 kilobase pairs (kb) of genomic DNA and comprise a portion of the human GalNAc-transferase 5'-and 3'-untranslated regions and the entire coding region. The human GalNAc-transferase gene structure consists of at least 11 exons ranging in size from 99 to > 620 nucleotides which are separated by 10 introns ranging in size from 0.7 to approximately 12.5 kb. The fourth genomic clone, P1-GALN-psi, contained a approximately 2.4 kb sequence region which shares an overall 78.6% nucleotide identity with coding region exons 1 and 3 through 11 of the human GalNAc-transferase gene. However, a lack of intron sequences, as well as the presence of multiple nucleotide mutations, insertions, and deletions that disrupt the potential GalNAc-transferase reading frame, suggest that P1.GALN-psi contains a processed pseudogene. Screening of a human/rodent somatic cell hybrid panel with a P1.GALN-psi probe localized the GalNAc-transferase pseudogene to chromosome 3. Hence, the human genome contains at least two related GalNAc-transferase genes that are located on separate chromosomes.
Meurer
J A
JA
Upjohn Company, Kalamazoo, MI 49001, USA.
Drong
R F
RF
Homa
F L
FL
Slightom
J L
JL
Elhammer
A P
AP
D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D002893:Chromosomes, Human, Pair 3; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005091:Exons; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics*; D011544:Pseudogenes; D012689:Sequence Homology, Nucleic Acid; D000097763:Polypeptide N-acetylgalactosaminyltransferase
D018076:DNA, Complementary; D017350:N-Acetylgalactosaminyltransferases; D000097763:Polypeptide N-acetylgalactosaminyltransferase