Scaffolding protein that assembles DMD and SNTA1 molecules to the basal membrane of kidney cells and liver sinusoids (By similarity). May function as a repressor of the SYN1 promoter through the binding of repressor element-1 (RE-1), in turn regulates SYN1 expression and may be involved in cell proliferation regulation during the early phase of neural differentiation (PubMed:27223470). May be required for proper maturation and function of a subset of inhibitory synapses (By similarity). {ECO:0000250|UniProtKB:O70585, ECO:0000269|PubMed:27223470}. This is the function of Ensembl gene identifier ENSG00000138101 (DTNB, dystrobrevin beta).