Structure and functional expression of the acid-labile subunit of the insulin-like growth factor-binding protein complex

1992 ◽  
Vol 6 (6) ◽  
pp. 870-876 ◽  
Author(s):  
S. R. Leong
Keyword(s):  
Growth Factor ◽  
Protein Complex ◽  
Binding Protein ◽  
Functional Expression ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Acid Labile Subunit ◽  
Acid Labile

scholarly journals Measurement of the acid-labile subunit of the insulin-like growth factor binding protein complex in human serum: a comparison of four immunoassays

2000 ◽  
Vol 165 (2) ◽  
pp. 271-279 ◽  
Author(s):  
RC Baxter ◽  
M Svejkar ◽  
MJ Khosravi ◽  
GL Bennett ◽  
KV Hardman ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Protein Complex ◽  
Binding Protein ◽  
Serum Marker ◽  
Healthy Children ◽  
Insulin Like Growth Factor ◽  
Factor Binding ◽  
Acid Labile Subunit ◽  
Acid Labile

The acid-labile subunit (ALS) of the high molecular weight insulin-like growth factor binding protein complex is a liver-derived glycoprotein which is regulated by growth hormone and serves as a serum marker of growth hormone action. We have compared the measurement of ALS by four immunoassay methods (two RIAs, two ELISAs) utilizing various polyclonal and monoclonal antibodies raised against natural or recombinant human ALS, or synthetic ALS peptides. Despite the variety of methodologies and reagents, results obtained by the four methods were highly correlated for 125 sera from various patient groups, and when compared for individual groups of sera from healthy children and adults, growth hormone-deficient children and adults, and subjects with acromegaly. Some weaker correlations among methods were seen when measuring ALS levels in groups of sera from pregnant subjects and subjects with chronic renal failure. An assay using antibodies raised against recombinant ALS yielded lower apparent values than the other methods in patient sera, the discrepancy probably being attributable to a difference in standardization. We conclude that a variety of assay formats and reagents can yield serum ALS values of potential clinical utility.

Cloning and characterization of the rat gene for the acid-labile subunit of the insulin-like growth factor binding protein complex

1997 ◽  
Vol 19 (3) ◽  
pp. 267-277 ◽  
Author(s):  
PJ Delhanty ◽  
RC Baxter
Keyword(s):  
Growth Factor ◽  
Protein Complex ◽  
Binding Protein ◽  
Luciferase Reporter ◽  
Insulin Like Growth Factor ◽  
Protein Coding ◽  
Factor Binding ◽  
Acid Labile Subunit ◽  
Acid Labile ◽  
Rat Genome

The acid-labile subunit (ALS) of the ternary insulin-like growth factor-binding protein complex has a central role in controlling the bioavailability of circulating insulin-like growth factors. We have shown that gene expression of ALS is regulated by a number of factors, particularly growth hormone. Our aim was to characterize the ALS gene in order to define the mechanism of its regulation. Southern analysis suggests a single copy of the ALS gene in the rat genome. The protein-coding and 3'-untranslated regions span approximately 3.5 kilobases of rat genome and are divided into two exons. The 5' flanking region of the gene lacks a consensus TATA-box or Inr sequence, and primer extension and reverse transcriptase PCR experiments locate multiple transcriptional initiation sites between -505 and -385 nucleotides relative to the translational initiation codon. This putative promoter region, when inserted upstream of the luciferase reporter gene, directs luciferase expression when transfected into H4-II-E cells. Our data demonstrate the uncomplicated structure of the rat ALS gene, and the promoter function and presence of potential regulatory elements in the region upstream of the protein-coding sequence.

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