Disease resistance protein of the TIR-NB-LRR-type (PubMed:14576290). Part of the RPP5 locus that contains a cluster of several paralogous disease resistance (R) genes (PubMed:14576290). Resistance proteins guard the plant against pathogens that contain an appropriate avirulence protein via an indirect interaction with this avirulence protein (PubMed:14576290). That triggers a defense system including the hypersensitive response, which restricts the pathogen growth (PubMed:14576290). Probably acts as a NAD(+) hydrolase (NADase): in response to activation, catalyzes cleavage of NAD(+) into ADP-D-ribose (ADPR) and nicotinamide; NAD(+) cleavage triggering a defense system that promotes cell death (PubMed:31439792). Expression regulated by MOS1 at chromatin level (PubMed:20647385). Nuclear localization of SNC1 is essential for its activity (PubMed:22454454). ABA deficiency can rescue high-temperature inhibition of SNC1-mediated defense responses (PubMed:22454454). H2O + NAD(+) = ADP-D-ribose + H(+) + nicotinamide Homodimer (PubMed:27818198). Interacts (via TIR domain) with TPR1 (PubMed:20647385). Interacts with EDS1 (PubMed:22158819). Interacts with SRFR1 (PubMed:21079790). Interacts with HSP90-3 (PubMed:24889324). Binds to MORC1/CRT1 (PubMed:20332379). Interacts with TRAF1B (PubMed:26867179). Restricted to microsomes when interacting with SRFR1. Accumulates in nucleus at 22 degrees Celsius, but not at 28 degrees Celsius. Nuclear accumulation is enhanced by abscisic acid deficiency. A number of isoforms are produced. According to EST sequences. Expressed in guard cells and epidermal cells, but not detected in mesophyll cells. Up-regulated by salicylic acid and in mutants defective in RNA silencing. Down-regulated by high temperature. Repressed by ZED1 in the absence of pathogens in an ambient temperature-sensitive manner (PubMed:28499073). The TIR domain mediates NAD(+) hydrolase (NADase) activity. Self-association of TIR domains is required for NADase activity. Met-1 is specifically acetylated by N-terminal acetyltransferase complex A (NatA). The NatA-mediated acetylation serves as a degradation signal. Met-1 is specifically acetylated by N-terminal acetyltransferase complex B (NatB). The NatB-mediated acetylation stabilizes SNC1. Impaired disease resistance responses. A gain-of-function mutant in SNC1 resulting from a point mutation leads to a dwarf and curled-leaf phenotype and a constitutive disease resistance in the absence of cell death. The phenotypically unstable bal phenotype is caused by a duplication of the locus carrying SNC1 followed by a hypermutation of the gene. SNC1 is not found in cv. Landsberg erecta, cv. No-0, and cv. Wassilewskija and is probably unique to cv. Columbia (PubMed:15031411). Cv. RLD encodes a non-functional truncated SNC1 protein lacking most of the LRR domain (PubMed:21079790). MOS2, MOS2H, MOS12 and the MOS4-associated complex (MAC) are required for the proper splicing of R genes and contribute in the alternative splicing of SNC1. Belongs to the disease resistance TIR-NB-LRR family.