Sequence of a cDNA clone encoding the Atlantic salmon alpha 1-microglobulin/bikunin protein

Area of Science:

• Evolutionary Biology
• Molecular Genetics
• Comparative Genomics

Background:

• Alpha 1-microglobulin/bikunin precursor protein (AMBP) is a multifunctional protein found in various species.
• Understanding the evolutionary history of AMBP can provide insights into gene evolution and protein function.
• Salmon (Salmo salar) represent a key lineage for studying vertebrate evolution.

Purpose of the Study:

• To determine the nucleotide sequence of the salmon alpha 1-microglobulin/bikunin precursor protein (sAMBP).
• To compare the amino acid sequence of sAMBP with homologous proteins in other species.
• To infer the evolutionary origins of the AMBP gene.

Main Methods:

• cDNA cloning and nucleotide sequencing of the salmon AMBP gene.
• Amino acid sequence analysis and comparison using bioinformatics tools.
• Phylogenetic analysis to estimate the divergence time of the ancestral AMBP gene.

Main Results:

• The nucleotide sequence of the sAMBP cDNA clone was successfully determined.
• The deduced amino acid sequence of sAMBP exhibits 36% and 42% similarity to the AMBP of pig and human, respectively.
• Conserved amino acid motifs within the AMBP precursor were identified, indicating functional importance.

Conclusions:

• The salmon AMBP precursor protein is evolutionarily conserved, sharing key features with mammalian orthologs.
• The data suggest that the ancestral AMBP gene originated over 450 million years ago.
• This ancient origin predates the divergence of tetrapods and fish, highlighting the deep evolutionary roots of this gene.