Revised nomenclature for High Mobility Group (HMG) chromosomal proteins [letter]

The high mobility group (HMG) chromosomal proteins were discovered in mammalian cells more than 30 years ago and named according to their electrophoretic mobility in polyacrylamide gels. Subsequent studies revealed that the functional motifs characteristic of the original, canonical, HMG proteins are widespread among nuclear proteins from various organisms. A systematic way to name this group of nuclear proteins has not yet been devised and the root symbol HMG presently serves as an identifier of several proteins that are not related to nuclear HMG proteins. In fact, a literature search with the term HMG (in PubMed) gives thousands of hits, >70% of which are not related to the nuclear HMGs.

To facilitate interactions between various laboratories, to expedite literature searches, and to avoid confusion due to similarity in the names of unrelated proteins, the nomenclature of the HMG nuclear proteins has been revised. The revisions are based on the guidelines endorsed by the mouse and human gene nomenclature committees, and on consultations with the staff of both the National Center for Biotechnology Information and the MESH Section at the National Library of Medicine in Bethesda, USA.

The HMG proteins are subdivided into 3 superfamilies: HMGB (root symbol, HMGB), HMGN (root symbol, HMGN) and HMGA (root symbol, HMGA) superfamily. Each HMG superfamily has a characteristic functional sequence motif. The functional motif of the HMGB family is called the HMG-box , that of the HMGN family, the nucleosomal binding domain , and that of the HMGA family, the AT-hook . Proteins containing any of these functional motifs embedded in their sequence are known as HMG motif proteins . The revisions, which have been applied to the canonical, mammalian HMG proteins, can be adapted to HMG-motif proteins from all organisms. The main features of the revised nomenclature are summarized in Table 1.

The new nomenclature establishes a set of rules and a systematic way to name the genes and proteins belonging to the High Mobility Group (HMG) families of nuclear proteins. The literature searches for the old and new HMG names are both forwards and backwards compatible. Thus, a PubMed search with a new term, HMGB1 , now, and in the future, will give the same result as a search with any of the old terms such as HMG1, HMG-1 or amphoterin. A search with HMG-14 in the future will still give all the entries with text words such as either HMG-14, HMG14 or HMGN1 (see table). A search with HMGB, HMGN, or HMGA will yield entries for all the members of that HMG family.

A full description of the HMG nomenclature and a list of the HMG proteins can be found at:
http://www.informatics.jax.org/mgihome/nomen/genefamilies/hmgfamily.shtml.

The new nomenclature was devised with the active participation of : Michael Bustin, NCI, NIH, Bethesda, Maryland, USA; David Landsman, NCBI, NLM, NIH, Bethesda, Maryland, USA; James Pash, MESH section, NLM, NIH, Bethesda, Maryland, USA; Marco E. Bianchi, San Rafaelle Research Institute, Milano, Italy; Ray Reeves, Washington State University, Pulman, Washington, USA; Klaus Grasser, Aalborg University, Denmark; Lois Maltais, Jackson Laboratory, Bar Harbor, USA; Vincenzo Giancotti, University of Trieste, Trieste, Italy; Jean Thomas, Cambridge, UK; Andrew Travers, Cambridge, UK. A list of additional scientists that agreed to have the HMG nomenclature revised is available on request.

Last updated: 08 January 2001
First published: 08 January 2001
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