Kopp et al 1995, proteasomeOne of the problems with genomics research is that the people who interpret it may not know much about the genes they identify. For example:

… single nucleotide polymorphisms (SNPs) in two genes critical for T-cell function are associated with susceptibility to MDD:1 PSMB4 (proteasome 4 subunit), important for antigen processing …2

Kopp et al 1995, HN3/PSMB4
PSMB4 location in proteasome3

OK, first of all, the proteasome is important in antigen processing, but antigen processing is probably about the least important of its myriad tasks. Suggesting that the function of the proteasome is antigen processing is like claiming the the function of my car is to hold coffee, because it happens to have cup-holders.4

Second, PSMB4 per se has never been implicated in antigen processing.5 Not only is it not one of the interferon-inducible trio of proteasome subunits that have been implicated in antigen processing, PSMB4 is not even catalytic.6

This looks like someone had a vague memory of seeing something in a textbook years ago, and didn’t try to look at the literature at all. Or who wanted to squeeze data into a preconceived theory.

  1. MDD: Major depressive disorder[]
  2. Wong ML, Dong C, Maestre-Mesa J, Licinio J.  Polymorphisms in inflammation-related genes are associated with susceptibility to major depression and antidepressant response. Mol Psychiatry. 2008 May 27. [Epub ahead of print] doi:10.1038/mp.2008.59 []
  3. Kopp F, Kristensen P, Hendil KB, Johnsen A, Sobek A, Dahlmann B. The human proteasome subunit HsN3 is located in the inner rings of the complex dimer. J Mol Biol. 1995 Apr 28;248:264-72 doi:10.1016/S0022-2836(95)80049-2 []
  4. Also, in my case, about 2000 little plastic dinosaurs, tucked into every cranny and hidden under the booster seats in the back.  I’m not sure what their function is either[]
  5. As far as I know; which is reasonably far[]
  6. Though it may be involved in proteolysis anyway.  But the point remains — not shown to have a role in antigen processing[]