Characterization of myocilin-myocilin interactions

Invest Ophthalmol Vis Sci. 2001 Sep;42(10):2324-31.


Purpose: To determine whether myocilin (MYOC; also referred to as TIGR) is present as a complex in human aqueous humor, whether part of the complex formation may be due to MYOC-MYOC interactions and to characterize the sites of interaction.

Methods: Human aqueous humor was analyzed by using a gel filtration column for the identification of MYOC complexes. MYOC-MYOC interactions were studied with a yeast two-hybrid system. Expression of full-length and truncated MYOC proteins in AH109 yeast was analyzed for growth and color on minimal medium. Site-directed mutagenesis was used to selectively mutate eight leucine residues within the leucine zipper motif. In vitro transcription and translation was used to verify yeast two-hybrid analysis.

Results: MYOC was found to be present in human aqueous humor as a complex ranging from 120 to 180 kDa. Expression of full-length MYOC in yeast as well as in vitro binding studies revealed that MYOC can interact with itself. MYOC-MYOC interactions occurred mainly within amino acids 117-166, a region containing a leucine zipper domain. Glycine substitution for selective leucine residues confirmed that MYOC-MYOC interactions occurred mainly within the leucine zipper domain.

Conclusions: MYOC is present in human aqueous humor, not as a monomer but as a complex. Part of this complex may form due to MYOC-MYOC interactions that take place mainly within the leucine zipper domain.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aqueous Humor / metabolism*
  • Chromatography, Gel
  • Cytoskeletal Proteins
  • Eye Proteins / metabolism*
  • Gene Expression
  • Glycoproteins / metabolism*
  • Humans
  • Leucine Zippers*
  • Mutagenesis, Site-Directed
  • Plasmids
  • Protein Binding
  • Saccharomyces / genetics
  • Transfection


  • Cytoskeletal Proteins
  • Eye Proteins
  • Glycoproteins
  • trabecular meshwork-induced glucocorticoid response protein