Elevated extrahepatic expression and secretion of mammary-associated serum amyloid A 3 (M-SAA3) into colostrum
| Autor: | David R. Mack, Thomas L. McDonald, Annika Weber, Marilynn A. Larson |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Signal peptide
Amino Acid Motifs Molecular Sequence Data Immunology Enzyme-Linked Immunosorbent Assay Biology Chromatography Affinity Mammary Glands Animal Complementary DNA Animals Protein Isoforms Amino Acid Sequence Horses Serum amyloid A Peptide sequence chemistry.chemical_classification Serum Amyloid A Protein Sheep Base Sequence Sequence Homology Amino Acid General Veterinary Molecular mass Reverse Transcriptase Polymerase Chain Reaction Colostrum DNA Sequence Analysis DNA Amino acid Molecular Weight Open reading frame Milk chemistry Biochemistry RNA Cattle Electrophoresis Polyacrylamide Gel Rabbits |
| Zdroj: | Veterinary Immunology and Immunopathology. 83:203-211 |
| ISSN: | 0165-2427 |
| DOI: | 10.1016/s0165-2427(01)00380-4 |
| Popis: | Mammary-associated serum amyloid A 3 (M-SAA3) was secreted at highly elevated levels in bovine, equine and ovine colostrum and found at lower levels in milk 4 days postparturition. N-terminal sequencing of the mature M-SAA3 protein from all the three species revealed a conserved four amino acid motif (TFLK) within the first eight residues. This motif has not been reported to be present in any of the hepatically-produced acute phase SAA (A-SAA) isoforms. Cloning of the bovine M-Saa3 cDNA from mammary gland epithelial cells revealed an open reading frame that encoded a precursor protein of 131 amino acids which included an 18 amino acid signal peptide. The predicted 113 residue mature M-SAA3 protein had a theoretical molecular mass of 12,826Da that corresponded with the observed 12.8kDa molecular mass obtained for M-SAA3 in immunoblot analysis. The high abundance of this extrahepatically produced SAA3 isoform in the colostrum of healthy animals suggests that M-SAA3 may play an important functional role associated with newborn adaptation to extrauterine life and possibly mammary tissue remodeling. |
| Databáze: | OpenAIRE |
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