Molecular cloning of the common acute lymphoblastic leukemia antigen (CALLA) identifies a type II integral membrane protein.
Common acute lymphoblastic leukemia antigen (CALLA) is a 100-kDa cell-surface glycoprotein expressed on most acute lymphoblastic leukemias and certain other immature lymphoid malignancies and on normal lymphoid progenitors. The latter are either uncommitted to B- or T-cell lineage or committed to only the earliest stages of B- or T-lymphocyte maturation. To elucidate to homogeneity, obtained the NH2-terminal sequence from both the intact protein and derived tryptic and V8 protease peptides and isolated CALLA cDNAs from a Nalm-6 cell line lambda gt10 library using redundant oligonucleotide probes. The CALLA cDNA sequence predicts a 750-amino acid integral membrane protein with a single 24-amino acid hydrophobic segment that could function as both a transmembrane region and a signal peptide. The COOH-terminal 700 amino acids, including six potential N-linked glycosylation sites compose the extracellular protein segment, whereas the 25 NH2-terminal amino acids remaining after cleavage of the initiation methionine form the cytoplasmic tail. CALLA+ cells contain CALLA transcripts of 2.7 to 5.7 kilobases with the major 5.7- and 3.7-kilobase mRNAs being preferentially expressed in specific cell types.
Shipp
M A
MA
Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, MA.
Richardson
N E
NE
Sayre
P H
PH
Brown
N R
NR
Masteller
E L
EL
Clayton
L K
LK
Ritz
J
J
Reinherz
E L
EL
D000595:Amino Acid Sequence; D000943:Antigens, Differentiation / Q000235:genetics*; D000951:Antigens, Neoplasm / Q000235:genetics*; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D006801:Humans; D007945:Leukemia, Lymphoid / Q000235:genetics / Q000276:immunology*; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics*; D015260:Neprilysin; D012334:RNA, Neoplasm / Q000032:analysis
D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; D004247:DNA; D015260:Neprilysin