Molecular cloning of human protein 4.2: a major component of the erythrocyte membrane
| Autor: | Lanping Amy Sung, Robert S. Schwartz, Long-Sheng Chang, Ronald L. Nagel, Shu Chien, Susan A. Bliss, Eric E. Bouhassira, Karel J. Lambert, Anne C. Rybicki |
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| Rok vydání: | 1990 |
| Předmět: |
Reticulocytes
Protein subunit Molecular Sequence Data Restriction Mapping Molecular cloning Biology Reticulocyte Sequence Homology Nucleic Acid Immunoscreening Complementary DNA medicine Humans Amino Acid Sequence Cloning Molecular Peptide sequence Gene Library Multidisciplinary Base Sequence cDNA library Erythrocyte Membrane Nucleic acid sequence Membrane Proteins Blood Proteins DNA Molecular biology Cytoskeletal Proteins medicine.anatomical_structure Biochemistry RNA Oligonucleotide Probes Research Article |
| Zdroj: | Proceedings of the National Academy of Sciences. 87:955-959 |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Protein 4.2 (P4.2) comprises approximately 5% of the protein mass of human erythrocyte (RBC) membranes. Anemia occurs in patients with RBCs deficient in P4.2, suggesting a role for this protein in maintaining RBC stability and integrity. We now report the molecular cloning and characterization of human RBC P4.2 cDNAs. By immunoscreening a human reticulocyte cDNA library and by using the polymerase chain reaction, two cDNA sequences of 2.4 and 2.5 kilobases (kb) were obtained. These cDNAs differ only by a 90-base-pair insert in the longer isoform located three codons downstream from the putative initiation site. The 2.4- and 2.5-kb cDNAs predict proteins of approximately 77 and approximately 80 kDa, respectively, and the authenticity was confirmed by sequence identity with 46 amino acids of three cyanogen bromide-cleaved peptides of P4.2. Northern blot analysis detected a major 2.4-kb RNA species in reticulocytes. Isolation of two P4.2 cDNAs implies existence of specific regulation of P4.2 expression in human RBCs. Human RBC P4.2 has significant homology with human factor XIII subunit a and guinea pig liver transglutaminase. Sequence alignment of P4.2 with these two transglutaminases, however, revealed that P4.2 lacks the critical cysteine residue required for the enzymatic crosslinking of substrates. |
| Databáze: | OpenAIRE |
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