Sad-1 And Unc-84 Domain Containing Protein 1 (SUN1)

The deduced protein contains 310 amino acids. Overall the mouse and human proteins share 75% homology, and they share 89% homology in the C-terminal Sad1/Unc84 (SUN) domain. Northern blot analysis of mouse tissues detected a 4.3-kb transcript in all tissues examined, with highest levels in heart, brain, and testis, and a 2.5-kb transcript only in testis. Northern blot analysis of isolated testicular germ cells detected the 4.3-kb transcript in pachytene spermatocytes and the 2.5-kb transcript primarily in postmeiotic cells. Unc84a transfected into NIH-3T3 mouse fibroblasts showed 2 patterns of distribution. One pattern was predominantly cytoplasmic with perinuclear accumulation, and the other exhibited both nuclear and cytoplasmic staining, but no accumulation in the nucleoli.