N-Oct 5 is generated by in vitro proteolysis of the neural POU-domain protein N-Oct 3.

Abstract

The neural POU-domain proteins N-Oct 3 and N-Oct 5 were first identified in electrophoretic mobility retardation assays through their ability to bind to the octamer sequence ATGCAAAT. These two N-Oct factors are detected in extracts from tumor-derived and normal neural cells. They are present differentially, however, in extracts from melanocytes and melanoma cells: N-Oct 3 is present in extracts from both melanocytes and melanoma cells, whereas N-Oct 5 is more evident in extracts from metastatic melanoma cells. We show here that a cDNA encoding N-Oct 3 directs synthesis of both the N-Oct 3 and N-Oct 5 proteins and that the N-Oct 5 protein in neural and melanoma-cell extracts is also related to N-Oct 3. N-Oct 5, however, is apparently not expressed in vivo: It is not detected if cells are rapidly lysed in SDS or if extracts are prepared with a cocktail of protease inhibitors that includes the serine-protease inhibitor 4-(2-Aminoethyl)benzenesulfonyl fluoride hydrochloride (AEBSF). These data suggest that N-Oct 5 is a specific in vitro proteolytic cleavage product of N-Oct 3 and is not directly related to melanocyte malignancy.

• Authors: S Atanasoski, E Schreiber, A Fontana, W Herr
• Journal: Oncogene (Oncogene) Vol. 14 Issue 11 Pg. 1287-94 (Mar 20 1997) ISSN: 0950-9232 [Print] England
• PMID: 9178889 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• DNA, Complementary
• Homeodomain Proteins
• POU Domain Factors
• Transcription Factors
• transcription factor Brn-2

Topics

• Animals
• Astrocytes (metabolism)
• COS Cells
• Cell Transformation, Neoplastic (genetics)
• DNA, Complementary
• Homeodomain Proteins
• Humans
• Hydrolysis
• Melanoma (genetics, pathology)
• POU Domain Factors
• Transcription Factors (genetics, metabolism)
• Tumor Cells, Cultured