In molecular biology, the DSS1/SEM1 protein family is a family of short acidic proteins which includes the 26S proteasome complex subunits SEM1 from Saccharomyces cerevisiae and Drosophila and DSS1 (SHFM1) in mammals. In Saccharomyces cerevisiae, SEM1 is a regulator of both exocyst function and pseudohyphal differentiation.[1] Loss of DSS1 in Homo sapiens (human) has been associated with split hand/split foot malformations.[2]
DSS1 is playing role as a modifier in a novel protein posttranslational modification, referred to as DSSylation, which is probably targeting oxidized proteins and guiding them to proteasomal degradation.[3]