High impact information on lin19

• We found that Nedd8 modifies Cul1 in Drosophila [1].
• In posterior cells, Ci degradation is controlled by a mechanism that requires the activity of Cul3, another member of the Cullin family [1].
• The ubiquitin-like protein, Nedd8, covalently modifies members of the Cullin family [1].
• These complexes are composed of three constant polypeptides--Skp1, Cullin1/3 and Roc1/Rbx1--and a fourth variable adapter, the F-box protein [2].
• We show that Encore physically interacts with the proteasome, Cul1 and Cyclin E [3].

Biological context of lin19

• Metal chelators and point mutations within JAMM abolished CSN-dependent cleavage of Nedd8 from Cul1, yet had little effect on CSN complex assembly [4].
• We propose that in encore mutant germaria the proteolysis machinery is less efficient and, in addition, reduced association of Cul1 and S1 with the fusome may compromise Cyclin E destruction and consequently promote an extra round of mitosis [3].

Regulatory relationships of lin19

• We propose that while Nedd8 promotes cullin activation through neddylation, neddylation also renders cullins unstable [5].

Other interactions of lin19

• Targeted disruption of Drosophila Roc1b reveals functional differences in the Roc subunit of Cullin-dependent E3 ubiquitin ligases [6].
• The association of Cul1, phosphorylated Cyclin E and the proteasome 19S-RP subunit S1 with the fusome is affected in encore mutant germaria [3].

References