A liver specific gene that is expressed in growth hormone transgenic mice and in normal female mice as a function of age

Growth Horm IGF Res. 2006 Jun;16(3):145-56. doi: 10.1016/j.ghir.2006.03.011. Epub 2006 May 24.


Growth hormone (GH) acts on various organs to exert its growth and metabolic effects. GH induces transcription of a number of genes in different organs including liver. By performing subtractive hybridization analysis on liver cDNAs of GH transgenic and non-transgenic mice, differentially expressed cDNAs were obtained. This paper describes the isolation and characterization of a liver cDNA, termed cDNA #5, that contains 1897 bp and is predicted to encode a protein (P5) of 512 aa residues. P5 has five immunoglobulin related domains thus allowing it to be classified as a member of the immunoglobulin super family (IGSF). Also, P5 shows significant similarity to both rat and human alpha-1-B glycoprotein which is an acidic serum protein of unknown function. mRNA #5 was detected in the liver hepatocytes of male and female GH transgenic mice and in the liver of female, but not of male, non-transgenic mice. mRNA #5 was not present in dwarf mice including the Ames dwarf, those that express a GH antagonist and those with the GH receptor and binding protein gene disrupted. These findings suggest that induction of mRNA #5 in the liver requires a continuous pattern of GH secretion and an intact GH-GH receptor-signaling complex. mRNA #5 levels in female non-transgenic mice were observed to vary with age implying that gender-specific age-dependent factor(s) may be involved in the induction of mRNA #5. The appearance of mRNA #5 in post-hepatectomized liver that coincides with the proliferative phase of liver regeneration suggests that it may be involved in hepatocyte proliferation. Together these data suggest that expression of cDNA #5 is liver-specific, sexually dimorphic, age-dependent, and may be involved in hepatocyte hyperplasia and liver enlargement.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • DNA, Complementary / metabolism
  • Female
  • Gene Expression Regulation, Developmental*
  • Glycoproteins / genetics*
  • Growth Hormone / genetics*
  • Growth Hormone / metabolism
  • Immunoglobulins
  • Liver / chemistry
  • Liver / metabolism*
  • Liver Regeneration / genetics*
  • Male
  • Mice
  • Mice, Transgenic
  • Molecular Sequence Data
  • RNA, Messenger / analysis
  • RNA, Messenger / metabolism
  • Receptors, Somatotropin / metabolism


  • A1bg protein, mouse
  • DNA, Complementary
  • Glycoproteins
  • Immunoglobulins
  • RNA, Messenger
  • Receptors, Somatotropin
  • Growth Hormone