Enables sphingolipid binding activity. Involved in several processes, including CD40 signaling pathway; regulation of gene expression; and regulation of phosphate metabolic process. Acts upstream of or within several processes, including mammary gland development; negative regulation of intracellular estrogen receptor signaling pathway; and negative regulation of mammary gland epithelial cell proliferation. Located in cell surface; mitochondrial inner membrane; and nucleus. Part of inner mitochondrial membrane protein complex. Is expressed in several structures, including alimentary system; genitourinary system; nervous system; nose; and respiratory system. Orthologous to human PHB2 (prohibitin 2). [provided by Alliance of Genome Resources, Apr 2022]