Genomic structure and chromosomal mapping of the human CD22 gene

Journal Article · Tue Jun 01 04:00:00 EDT 1993 · Journal of Immunology; (United States)

OSTI ID:6180384

Wilson, G L; Kozlow, E; Kehrl, J H ^[1]; Najfeld, V ^[2]; Menniger, J; Ward, D ^[3]

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1. National Institutes of Health, Bethesda, MD (United States)
2. Mount Sinai Medical Center, New York, NY (United States)
3. Yale School of Medicine, New Haven, CT (United States)

The human CD22 gene is expressed specifically in B lymphocytes and likely has an important function in cell-cell interactions. A nearly full length human CD22 cDNA clone was used to isolate genomic clones that span the CD22 gene. The CD22 gene is spread over 22 kb of DNA and is composed of 15 exons. The first exon contains the major transcriptional start sites. The translation initiation codon is located in exon 3, which also encodes a portion of the signal peptide. Exons 4 to 10 encode the seven Ig domains of CD22, exon 11 encodes the transmembrane domain, exons 12 to 15 encode the intracytoplasmic domain of CD22, and exon 15 also contains the 3' untranslated region. A minor form of CD22 mRNA likely results from splicing of exon 5 to exon 8, skipping exons 6 and 7. A 4.6-kb Xbal fragment of the CD22 gene was used to map the chromosomal location of CD22 by fluorescence in situ hybridization. The hybridization locus was identified by combining fluorescent images of the probe with the chromosomal banding pattern generated by an Alu probe. The results demonstrate the CD22 is located within the band region q13.1 of chromosome 19. Two closely clustered major transcription start sites and several minor start sites were mapped by primer extension. Similarly to many other lymphoid-specific genes, the CD22 promoter lacks an obvious TATA box. Approximately 4 kb of DNA 5' of the transcription start sites were sequenced and found to contain multiple Alu elements. Potential binding sites for the transcriptional factors NF-kB, AP-1, and Oct-2 are located within 300 bp 5' of the major transcription start sites. A 400-bp fragment (bp -339 through +71) of the CD22 promoter region was subcloned into a pGEM-chloramphenicol acetyltransferase vector and after transfection into B and T cells was found to be active in both B and T cells. 45 refs., 7 figs., 2 tabs.

• OSTI ID: 6180384
• Journal Information: Journal of Immunology; (United States), Journal Name: Journal of Immunology; (United States) Vol. 150:11; ISSN 0022-1767; ISSN JOIMA3
• Country of Publication: United States
• Language: English

Related Subjects

550400* -- Genetics
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANTIGENS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CHROMOSOMES
CLONING
CONNECTIVE TISSUE CELLS
DNA HYBRIDIZATION
DNA SEQUENCING
DNA-CLONING
GENE REGULATION
GENE REPRESSORS
GENES
HUMAN CHROMOSOME 19
HUMAN CHROMOSOMES
HYBRIDIZATION
LEUKOCYTES
LYMPHOCYTES
MAPPING
MATERIALS
SOMATIC CELLS
STRUCTURAL CHEMICAL ANALYSIS
TRANSCRIPTION FACTORS