Human genome: proto-oncogenes and proretroviruses

Area of Science:

• Molecular Biology
• Genetics
• Oncogenesis

Background:

• The human genome contains dispersed nucleotide sequences related to the proto-oncogene mos and proretroviral sequences.
• These regions are found in tight juxtaposition within the genome.

Purpose of the Study:

• To analyze specific human DNA fragments containing proto-mos and proretroviral sequences.
• To investigate the structure and potential function of these genomic regions.

Main Methods:

• DNA sequencing of cloned fragments in phage and plasmid vectors.
• Analysis of RNA transcripts from proretroviral-like sequences.

Main Results:

• Identified NV-1 as a pseudogene of proto-mos with partial duplications and intervening Alu elements.
• Identified CL-1 as a mos-related gene with a deletion, flanked by a proretroviral-like sequence.
• Proretroviral-like sequences are transcribed into abundant poly(A)+RNA in human cells.

Conclusions:

• Endogenous retroviruses may participate in the amplification of proto-oncogenes.
• Proto-oncogenes can be inactivated by insertion of movable genetic elements, forming pseudogenes.
• Human genome's potential oncogenicity is influenced by opposing forces of proto-oncogene amplification and inactivation.