title: The liver-specific human alpha(1)-microglobulin/bikunin precursor (AMBP) is capable of self-association.
abstract: alpha-1-Microglobulin (A1M) and bikunin are two plasma glycoproteins encoded by an alpha-1-microglobulin/bikunin precursor (AMBP) gene. Despite their lack of any structural or functional relationship, both A1M and bikunin originate from AMBP cleavage by a furin-like protease that releases the two mature molecules. The AMBP gene maintains a tight control over its expression by a unique enhancer, which is controlled by several hepatocyte-enriched nuclear factors; however, the mechanisms of regulation of the intracellular levels of the AMBP protein are currently unknown. We report the ability of the AMBP protein to self-associate and form a dimer in a yeast environment using the yeast two-hybrid system and an in vitro dimerization assay. We also show that the A1M protein binds to its precursor protein, AMBP, whereas bikunin does not. This observation warrants further investigations for a dimerization-dependent intracellular control that AMBP may be involved in. The relevance of AMBP dimerization and its possible biological significance are postulated.
authors.affiliation: Virology Group, International Centre for Genetic Engineering & Biotechnology, Aruna Asaf Ali Road, New Delhi, 110067, India.
authors.forename: Shweta
authors.initials: S
authors.lastname: Tyagi
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Salier
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Lal
mesh_terms: D000510:Alpha-Globulins / Q000378:metabolism; D019281:Dimerization; D006801:Humans; D008099:Liver / Q000737:chemistry*; D008562:Membrane Glycoproteins / Q000378:metabolism; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D012712:Serum Globulins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014360:Trypsin Inhibitor, Kunitz Soybean; D020798:Two-Hybrid System Techniques; D015003:Yeasts / Q000235:genetics
chemical_list: D000510:Alpha-Globulins; D008562:Membrane Glycoproteins; D011498:Protein Precursors; C109148:SPINT2 protein, human; D012712:Serum Globulins; C016001:alpha-1-microglobulin; D014360:Trypsin Inhibitor, Kunitz Soybean