Substrate-specific adapter of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex that mediates ubiquitination of Ras (K-Ras/KRAS, N-Ras/NRAS and H-Ras/HRAS) (PubMed:30442762). Is a negative regulator of RAS-MAPK signaling that acts by controlling Ras levels and decreasing Ras association with membranes (PubMed:30442762). Protein modification; protein ubiquitination. Homodimer. Component of the BCR(LZTR1) E3 ubiquitin ligase complex, at least composed of CUL3, LZTR1 and RBX1. Interacts with Ras (K-Ras/KRAS, N-Ras/NRAS and H-Ras/HRAS). Interacts with RAF1. Interacts with SHOC2. Interacts with PPP1CB. Widely expressed. Phosphorylated on tyrosine upon induction of apoptosis, leading to its degradation by the proteasome. Embryonic lethality between 17.5 dpc and birth (PubMed:30442762). Impaired ubiquitination of Ras (K-Ras/Kras, N-Ras/Nras and H-Ras/Hras) (PubMed:30442762). Heterozygous mice display heart malformations, including decreased left ventricular systolic function, increased diastolic dimensions, eccentric hypertrophy, increased cardiomyocyte area and reduced longevity; phenotypes that are reminiscent of human Noonan Syndrome (PubMed:30442762). May result from the retention of an intron in the cDNA in position 800. Belongs to the LZTR1 family.