SLMB binds to and ubiquitinates phosphorylated cytosolic PER

Stable Identifier
Reaction [transition]
Drosophila melanogaster
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During the day, with levels of it's stabilising partner Timeless (TIM) drastically reduced by light, hyperphosphorylated Period (PER) becomes a target for the F-box containing protein, supernumerary limbs (SLMB). Ser47 phosphorylation of Period (PER) appears to be the trigger for SLMB to bind to and ubiquitinate phosphorylated PER, marking it for processing by the 26S proteasome. In this model for the Circadian Clock pathway we are assuming that the cytoplasmic and nuclear mechanisms for PER degradation are the same.

Literature References
PubMed ID Title Journal Year
12442174 Role for Slimb in the degradation of Drosophila Period protein phosphorylated by Doubletime

Ko, HW, Jiang, J, Edery, I

Nature 2002
12432393 The F-box protein slimb controls the levels of clock proteins period and timeless

Grima, B, Lamouroux, A, Chélot, E, Papin, C, Limbourg-Bouchon, B, Rouyer, F

Nature 2002
18593878 The phospho-occupancy of an atypical SLIMB-binding site on PERIOD that is phosphorylated by DOUBLETIME controls the pace of the clock

Chiu, JC, Vanselow, JT, Kramer, A, Edery, I

Genes Dev 2008
Participant Of
Catalyst Activity
Catalyst Activity
ubiquitin-protein transferase activity of SLMB [cytosol]
Physical Entity