Unconventional secretion of tubby and tubby-like protein 1

作者：Caberoy, Nora B.; Li, Wei^*

来源：FEBS LETTERS, 2009, 583(18): 3057-3062.

DOI：10.1016/j.febslet.2009.08.015

• Tubby
• Tubby-like protein 1
• Unconventional secretion
• Extracellular trafficking
• Obesity
• Retinal degenerations

Tubby-like proteins (Tulps) with no signal peptide have been characterized as cytoplasmic proteins with various intracellular functions, including binding to phosphatidylinositol-4,5-bisphosphate [PI(4,5)P-2]. PI(4,5)P-2 has been implicated in unconventional secretion of. broblast growth factor-2 without a signal peptide. Here, we show that all Tulps are expressed intracellularly and extracellularly. Tubby secretion is partially dependent on its PI(4,5)P-2-binding activity with an essential secretory signal in the N-terminus. Pathogenic mutation in Tubby mice has no impact on tubby extracellular trafficking. Moreover, unconventional secretion of tubby and Tulp1 is independent of endoplasmic reticulum-Golgi pathway. These data implicate that Tulps may function extracellularly as well.

• 出版日期2009-9-17