Catalytic subunit of the probable trimeric SNF1-related protein kinase (SnRK) complex, a central regulator of cellular energy homeostasis, which, in response to seemingly unrelated darkness, sugar and stress conditions, activates energy-producing pathways and inhibits energy-consuming processes. May play a role in a signal transduction cascade regulating gene expression and carbohydrate metabolism in higher plants. The SnRK complex may also be involved in the regulation of fatty acid synthesis by phosphorylation of acetyl-CoA carboxylase and in assimilation of nitrogen by phosphorylating nitrate reductase (PubMed:17671505). In vitro, KIN11 exhibits kinase activity on sucrose phosphate synthase and the kinase activity is inhibited by PRL1 (PubMed:10220464). May be a subunit of a SCF ubiquitin ligase complex and thus be involved in proteasomal ubiquitination (PubMed:11387208). Involved in innate antiviral defenses (PubMed:12671096). Phosphorylates REM4.1 in vitro (PubMed:25289013). Phosphorylates ADK2 in vitro (PubMed:24498147). ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Inactivated by the begomovirus AL2 protein or the curtovirus L2 protein (PubMed:12671096). Activated by phosphorylation at Thr-176 by GRIK1/SNAK2 and GRIK2/SNAK1 (PubMed:19339507). Inhibited by trehalose-6-phosphate (PubMed:19193861). Subunit of a probable heterotrimeric complex consisting of an alpha catalytic (KIN10 or KIN11) subunit, and a beta (KINB) and a gamma (KING or SNF4) non-catalytic regulatory subunits (PubMed:17028154, PubMed:25736509). Interacts with KINB2, KINB3, SNF4 and probably with KINB1 and KING1 (PubMed:10417704, PubMed:10929106, PubMed:11522840, PubMed:15803412, PubMed:17028154). Interacts with SKP1/ASK1, PAD1 and the N-terminus of PRL1 (PubMed:10220464, PubMed:11387208). Potential subunit of a SCF ubiquitin ligase complex consisting of a SNF1-related protein kinase, SKP1 and CUL1. The association of the SCF complex with the proteasome may be mediated by PAD1 and seems to be inhibited by the interaction with PRL1 (PubMed:11387208). Interacts with DSP4 (PubMed:12148529). Interacts with the begomovirus AL2 protein and the curtovirus L2 protein (PubMed:12671096). Interacts with ATAF1 (Ref.20). Interacts with CIPK14 (PubMed:25058458). Interacts with FLZ proteins through their FLZ-type zinc finger domains (PubMed:24600465, PubMed:29945970). Interacts with GEBP/STKR1 (PubMed:24600465, PubMed:29192025). Interacts with REM4.1 and REM4.2 (PubMed:25289013). Interacts with ADK2 (PubMed:24498147). Interacts with IDD8 (PubMed:25929516). Interacts with FLZ3, FLZ9, TCP3, TCP13, HB21/ZHD3 and HB23/ZHD10 (Ref.32). Interacts with WRI1 (PubMed:28314829). Interacts with IPK2b (PubMed:29216370). Interacts with FLZ6 and FLZ10 (PubMed:29406622). Co-localized with ER marker when associated with FLZ6 or FLZ10. Expressed in roots, shoots, flower buds, flowers, siliques and leaves (PubMed:10417704). Restrictly expressed to the base of the leaf, the vascular tissue, and the hydathodes (PubMed:25071807). Induced by sucrose (PubMed:10220464). Down-regulated under phosphate starvation (at the protein level) (PubMed:19211700). Up-regulated by beta-aminobutyric acid (BABA) (PubMed:20484986). Induced after infection by the effector avirulence protein AvrRpm1 from P.syringae (PubMed:27337039). Induced by trehalose (PubMed:25071807). The regulatory domain (RD) contains the auto-inhibitory domain (AID) that inhibits kinase activity of the protein kinase domain (KD). The PPI motif mediates the interaction with the ABI (abscisic acid-insensitive) phosphatases. Sumoylated by SIZ1. Phosphorylated at Thr-176 under submergence (PubMed:27029354). Autophosphorylated (PubMed:10220464). Phosphorylated at Thr-176 by GRIK1/SNAK2 and GRIK2/SNAK1 (PubMed:19339507). Increased seed abortion. Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. SNF1 subfamily.