Retroelements and the Human Genome: New Perspectives on an Old Relation

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 101; no. Suppl 2; pp. 14572 - 14579
• Main Authors: Bannert, Norbert, Kurth, Reinhard
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 05.10.2004; National Acad Sciences
• Series: Colloquium Paper
• Subjects: Antibodies, Viral - biosynthesis; Colloquium Papers; Endogenous Retroviruses - genetics; Endogenous Retroviruses - isolation & purification; Endogenous Retroviruses - ultrastructure; Evolution, Molecular; Gene Expression; Genes; Genetic diversity; Genome, Human; Genomes; Genomics; Germ cells; Human endogenous retrovirus; Humans; Microscopy, Electron; Mutation; Open reading frames; Proviruses; Proviruses - genetics; Proviruses - isolation & purification; Retroelements; Retrotransposons; Retroviridae; Retroviridae Proteins - genetics; Retroviridae Proteins - immunology; Tumors; Viruses
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0404838101

Retroelements constitute a large portion of our genomes. One class of these elements, the human endogenous retroviruses (HERVs), is comprised of remnants of ancient exogenous retroviruses that have gained access to the germ line. After integration, most proviruses have been the subject of numerous amplifications and have suffered extensive deletions and mutations. Nevertheless, HERV-derived transcripts and proteins have been detected in healthy and diseased human tissues, and HERV-K, the youngest, most conserved family, is able to form virus-like particles. Although it is generally accepted that the integration of retroelements can cause significant harm by disrupting or disregulating essential genes, the role of HERV expression in the etiology of malignancies and autoimmune and neurologic diseases remains controversial. In recent years, striking evidence has accumulated indicating that some proviral sequences and HERV proteins might even serve the needs of the host and are therefore under positive selection. The remarkable progress in the analysis of host genomes has brought to light the significant impact of HERVs and other retroelements on genetic variation, genome evolution, and gene regulation.