Molecular cloning of the common acute lymphoblastic leukemia antigen (CALLA) identifies a type II integral membrane protein

Proc Natl Acad Sci U S A. 1988 Jul;85(13):4819-23. doi: 10.1073/pnas.85.13.4819.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Antigens, Differentiation / genetics*
  • Antigens, Neoplasm / genetics*
  • Base Sequence
  • DNA / genetics
  • Humans
  • Leukemia, Lymphoid / genetics
  • Leukemia, Lymphoid / immunology*
  • Membrane Proteins / genetics*
  • Molecular Sequence Data
  • Neoplasm Proteins / genetics*
  • Neprilysin
  • RNA, Neoplasm / analysis


  • Antigens, Differentiation
  • Antigens, Neoplasm
  • Membrane Proteins
  • Neoplasm Proteins
  • RNA, Neoplasm
  • DNA
  • Neprilysin

Associated data

  • GENBANK/J03779