The fat and thin of lipin.

Mutations in the Lpin1 gene (encoding lipin) cause the lipodystrophy (adipose tissue deficiency) of the fld mouse, but the underlying mechanism has been unclear. In this issue of Cell Metabolism, Phan and Reue (2005) show that overexpression of lipin in either muscle or adipose tissue increases adiposity. Interestingly, mice overexpressing lipin in muscle are insulin resistant, while those overexpressing lipin in adipose tissue are insulin sensitive.