THG-1pit moves to nucleus at the onset of cerebellar granule neurons apoptosis

Thg-1pit (Tsc22d4), a murine gene belonging to the TGF-beta 1-stimulated clone 22 domain (TSC22D) family, is expressed in developing and adult cerebellar granule neurons and mature Purkinje cells. We have studied TFG-1pit function in primary cultures of mouse cerebellar granule neurons maintained in vitro in the presence of a medium containing 25 mM K+ (differentiating condition) or 5 mM K+ (pro-apoptotic condition), and determined the effect Of Culture medium, rGF-beta 1 and IGF-1 on THG-1 pit expression and intracellular localization. Thg-1pit encoded a 42 kDa MW protein and other, higher MW and developmentally-regulated forms. Cell exposure to 5 mM K+ elicited early and/or late wives of Thg-1pit transcription, depending on the presence/absence of TGF-beta 1, and Caused THG-1 pit to massively and transiently move from cytoplasm and neurites to the nucleus. THG-1pit nuclear entrance was concomitant to that of AIF, Suggesting that THG-1pit is involved in the induction of granule neuron apoptosis. (C) 2008 Elsevier Inc. All rights reserved.