Correction
for Goldfine et al., Endocr Rev 29 (1) 62-75.
Endocrine Reviews 30 (1): 117
Copyright © 2009 by The Endocrine Society
Corrigendum
In the February 2008 Endocrine Reviews article by I.D. Goldfine et al., "The Role of Membrane Glycoprotein Plasma Cell Antigen 1/Ectonucleotide Pyrophosphatase Phosphodiesterase 1 in the Pathogenesis of Insulin Resistance and Related Abnormalities" (Endocr Rev 29:62–75, 2008), the authors request that the abstract read as follows: Insulin resistance is a major feature of most patients with type 2 diabetes mellitus (T2D). A number of laboratories have observed that PC-1 (membrane glycoprotein plasma cell antigen 1; also termed ectonucleotide pyrophosphatase phosphodiesterase 1 or ENPP1) is either overexpressed or overactive in muscle, adipose tissue, fibroblasts, and other tissues of insulin-resistant individuals, both nondiabetic and diabetic. Moreover, PC-1 (ENPP1) overexpression in cultured cells in vitro and in transgenic mice in vivo, impairs insulin stimulation of insulin receptor (IR) activation and downstream signaling. PC-1 binds to the connecting domain of the IR 
-subunit that is located in residues 485–599. The connecting domain transmits insulin binding in the -subunit to activation of tyrosine kinase activation in the β-subunit. When PC-1 is overexpressed, it inhibits insulin induced IR β-subunit tyrosine kinase activity. In addition, a polymorphism of PC-1 (K121Q) in various ethnic populations is closely associated with insulin resistance, T2D, and cardio and nephrovascular diseases. The product of this polymorphism has a 2- to 3-fold increased binding affinity for the IR and is more potent than the wild-type PC-1 protein (K121K) in inhibiting the IR. These data suggest therefore that PC-1 is a candidate protein that may play a role in human insulin resistance and T2D by its overexpression, its overactivity, or both.
