Probably inactive kinase (PubMed:28751315). Component of the AP2-containing clathrin coat that regulates clathrin-dependent trafficking at plasma membrane, TGN and endosomal system (PubMed:28751315). Together with SCYL2B, required for cell growth, plant growth and development (PubMed:28751315). Essential for polarized root hair development probably by mediating the root hair tip localization of cellulose synthase-like D3 (CSLD3) (PubMed:28751315). Interacts with VTI11, VTI12 and CHC1. Colocalizes with the clathrin heavy chain 1 (CHC1). Expressed in roots, seedlings, leaves, stems, flowers, and, at low levels, in siliques. Expressed in shoot and root vascular tissues (PubMed:28751315). In root cap regions, accumulates in columella cells and lateral root caps (PubMed:28751315). Also observed specialized cell types such as trichomes, guard cells and root hairs (PubMed:28751315). The protein kinase domain is predicted to be catalytically inactive. Abnormal root hair development (e.g. shorter with abnormal shapes) (PubMed:28751315). The double mutant scyl2a scyl2b has short root hairs and small shoots (PubMed:28751315). Belongs to the protein kinase superfamily. Although it belongs to the kinase superfamily, lacks the residues involved in ATP binding, suggesting that it has no protein kinase activity.