Table 3 Suggested practical differences between ULK1 and ULK2.

‘Organic substance catabolic process’ and ‘carbohydrate metabolic process’ is a significant GO term shared between interactors of ULK1 but not ULK2

In HCT116 cells ULK1, but not ULK2 knockdown reduces the glucose consumption significantly

Li et al., 2016³¹

Interacting partners of ULK1 share the GO term for cellular response to stress; presence of a phosphorylation site (DOC_Cyclin_RxL_1: Cyclin docking motif), specific to ULK1, on which cyclin/Cdk complexes involved in different biological processes, such as stress response can influence ULK1

MEFs display a better colocalization of stress granules and ULK1 (compared to the colocalization of TIA1 and ULK2)

In MEFs the contribution of Ulk2 to genotoxic stress-induced alternative autophagy appears to be small

Wang et al., 2019³⁴

Torii et al., 2020⁴⁶

The apoptotic process is one of the significant GO terms that is shared among the transcription factors of ULK1

ULK1 acts as an anti-apoptotic protein however to our knowledge no information is available about ULK2

Wang et al., 2018³⁸; Dower et al., 2018³⁹

Transcription factors of ULK2, but not ULK1, are annotated to be significant in homeostasis

ULK2, opposed to ULK1, has previously been also shown to be essential for degradation of ubiquitinated proteins and homeostasis in skeletal muscle

Fuqua et al., 2019¹⁶

ULK2 harbours a TRAF6 binding site (LIG_TRAF6 motif), which is responsible for a response to the tumor necrosis factor receptor (TNFR) superfamily, and direct interaction with various TNF cytokine receptors. The presence of the TRAF6 binding site motif on ULK2 but not on ULK1 underlines the finding that ULK2-specific transcriptional regulators share the function for response to cytokines

In two microarray datasets, ULK2 is downregulated in colon biopsies from inactive UC compared to healthy patients

GEO: GSE6731⁴⁴, GSE53306⁴⁵