Suppressor Of Ty 4 Homolog 1 (SUPT4H1)

SUPT4H1 was expressed as 1.7- and 0.9-kb mRNAs in all human tissues tested. The 2 transcripts appeared to result from the use of alternative polyadenylation sites. The predicted 117-amino acid human protein is 42% identical to Spt4. Both proteins contain an N-terminal zinc finger motif. Using immunofluorescence, the authors found that epitope-tagged SUPT4H protein localized to the nucleus.

D-ribofuranosylbenzimidazole sensitivity-inducing factor (DSIF), a heterodimer of SPT4 and SPT5 (SUPT5H), repressed or activated transcription elongation by RNA polymerase II in HeLa cells based on the phosphorylation status of SPT5.when expressed in yeast, SUPT4H partially complemented all Spt4-null mutation phenotypes tested.