A small CSN3-containing complex, but not the CSN, is affected by the <i>csn3-3</i> mutation.

<p>Protein extracts from 7-d.o. Col, <i>csn1-10</i> and <i>csn3-3</i> seedlings were fractionated on a Superdex-200 gel filtration column and fractions (4 to 19) were collected and blotted with α-CSN1, α-CSN4, and α-CSN8 (<b>A</b>), α-CSN5 (<b>B</b>) and α-CSN3 (<b>C</b>). Fraction #4 was lost in the experiment examining CSN8. In (<b>C</b>), the assembly of a small CSN3-containing protein complex was observed in fractions 12-14. This complex was absent in <i>csn3-3</i> extracts, but was restored by introduction of a genomic <i>CSN3</i> transgene (L4 complementation line). Molecular mass standards are shown at the bottom of each panel. EX indicates the protein crude extract before gel filtration. (<b>D</b>) CSN3 protein level is unaffected by the <i>csn3-3</i> mutation. RPT5 is shown as a loading control.