Kelch Like Protein 42 (KLHL42)

The Cul3/Klhdc5 E3 ligase regulates p60/katanin and is required for normal mitosis in mammalian cells. E3 ubiquitin ligases are involved in targeting specific substrates for degradation by facilitating their ubiquitination.

Overexpression of Ctb9/KLHDC5 resulted in an increase in microtubule density as well as persistent microtubule bridges between post-mitotic cells. Conversely, down-regulation of Ctb9/KLHDC5 showed a pronounced reduction in microtubule density. p60/katanin interacts with a complex consisting of Cul3 and Ctb9/KLHDC5, which results in ubiquitin laddering of p60/katanin. Also, Cul3-deficient cells or Ctb9/KLHDC5-deficient cells show an increase in p60/katanin levels, indicating that Cul3/Ctb9/KLHDC5 is required for efficient p60/katanin removal.