Suprabasin (SBSN)

Sbsn contains an N-terminal transmembrane domain, a central domain with glycine-, alanine-, and histidine-rich short tandem repeats, and several phosphorylation and myristoylation sites. An alternatively spliced transcript encodes a protein lacking the central repetitive region. In situ hybridization of embryonic and adult mice showed Sbsn expression in the suprabasal layers of the epithelia in tongue, stomach, and epidermis. Northern and RNA dot blot analyses of adult mouse tissues revealed expression in uterus and thyroid, but not in heart, brain, spleen, lung, liver, smooth muscle, and kidney. Fluorescence-tagged Sbsn showed a punctate cytoplasmic distribution in transfected mouse keratinocytes that did not overlap with lysosomal or mitochondrial markers.