Enables mitogen-activated protein kinase binding activity. Involved in negative regulation of osteoblast differentiation; regulation of bone mineralization; and regulation of stress-activated MAPK cascade. Located in late endosome; mitochondrial intermembrane space; and phagophore assembly site. Colocalizes with autophagosome. Is expressed in several structures, including brain; cardiovascular system; genitourinary system; gut; and immune system. Orthologous to human NBR1 (NBR1 autophagy cargo receptor). [provided by Alliance of Genome Resources, Apr 2022]