High impact information on SHR3

• Mutations in SHR3 block amino acid uptake into yeast by reducing the levels of multiple amino acid permeases within the plasma membrane [1].
• The integral endoplasmic reticulum (ER) membrane protein Shr3p is required for proper plasma membrane localization of amino acid permeases (AAPs) in yeast [2].
• In contrast, the packaging of the plasma membrane ATPase, Pma1p, and the soluble yeast pheromone precursor, glycosylated pro alpha factor, was independent of Shr3p [3].
• In S. cerevisiae lacking SHR3, amino acid permeases specifically accumulate in membranes of the endoplasmic reticulum (ER) and fail to be transported to the plasma membrane [3].
• Amino acid permeases require COPII components and the ER resident membrane protein Shr3p for packaging into transport vesicles in vitro [3].

Biological context of SHR3

• For this purpose, an shr3 mutant was transformed with an Arabidopsis cDNA library [4].
• Shr3p, an ER protein that participates in the biogenesis of amino acid permeases was also required for the functional expression of Ca-Can1p [5].

Anatomical context of SHR3

• The SHR3 gene of Saccharomyces cerevisiae encodes an integral membrane component of the endoplasmic reticulum (ER) with four membrane-spanning segments and a hydrophilic, cytoplasmically oriented carboxyl-terminal domain [6].

Associations of SHR3 with chemical compounds

• Thus, leflunomide is suggested to affect amino acid transport by interacting with Shr3 chaperon-like protein [7].

Regulatory relationships of SHR3

• DNA sequencing analysis indicates that the MLF4 gene is identical to the SSH4 gene which suppresses the shr3 mutation [7].

Other interactions of SHR3

• Pulse-chase experiments indicate that the Shr3p-Gap1p association is transient, a reflection of the exit of Gap1p from the ER [6].
• Ssy1p requires the endoplasmic reticulum protein Shr3p, the amino acid permease-specific packaging chaperonin, to reach the PM, whereas Ptr3p does not [8].

References