Figure 5.—

Htz1p contributes to Kar2p secretion via Golgi-ER retrieval. Secretion of Kar2p was detected in the indicated strains by immunoblotting of the extracellular medium (top) and total cellular protein was monitored by immunoblotting of the plasma membrane protein, Yor1p (bottom). (A) Kar2p secretion in htz1Δ cells was equivalent regardless of sir2Δ and hmrΔ deletion. (B) Secretion of Kar2p correlates specifically with the K14R acetylation-deficient mutant of Htz1p. (C) Kar2p secretion in an htz1Δ mutant was not rescued by overexpression of ILM1. Cells expressing the empty vector, pRS426, serve as a negative control. (D) The punctate distribution of Erd2p-GFP in htz1Δ cells (left) was restored to an ER localization by overexpression of SEC22 (middle), but not BET1 (right).