Premium
Role of Glutathione S‐Transferase Activity in Endoplasmic Reticulum Chaperone DsbA‐L in the Assembly of Adipocyte Homrone Adiponectin
Author(s) -
Kartchner Laurel B.,
Malinowski Pamela,
Tsao TsuShuen
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.919.2
Subject(s) - dsba , adiponectin , endoplasmic reticulum , chemistry , adipocyte , chaperone (clinical) , protein disulfide isomerase , biochemistry , insulin , endocrinology , insulin resistance , biology , medicine , adipose tissue , gene , escherichia coli , pathology , periplasmic space
Adiponectin is an adipocyte‐derived hormone with anti‐inflammatory and insulin‐sensitizing actions. Adiponectin circulates as trimers, hexamers, and higher molecular weight (HMW) species. Studies have shown HMW adiponectin is the most active, but the assembly of HMW adiponectin is poorly understood. DsbA‐L is a protein present in the endoplasmic reticulum (ER) that has been shown to increase production of HMW adiponectin. DsbA‐L is also known as mGST‐k with glutathione S‐transferase activity (GST). To determine the mechanism by which DsbA‐L promotes HMW adiponectin assembly, we examined whether DsbA‐L's ability to increase HMW adiponectin is dependent upon its GST activity. DsbA‐L with S16A substitution in the critical SXXS motif could not promote HMW adiponectin oligomerization but S19A substitution could. We recombinantly expressed and purified his‐tagged wild‐type (WT), S16A, and S19A DsbA‐L using nickel affinity chromatography and will test whether they have GST activity. If GST activity is found in WT and S19A DsbA‐L but not in S16A DsbA‐L, then it supports the hypothesis that GST activity is necessary for increased adiponectin oligomerization due to DsbA‐L. If S16A DsbA‐L retains normal GST activity, then it likely serves as a chaperone for adiponectin. These studies could potentially uncover the causes responsible for decreased concentrations of HMW adiponectin associated with type 2 diabetes.