Cloning and characterization of the mouse <i>Arht2</i> gene which encodes a putative atypical GTPase

Abstract

ARHT is a new subgroup of the Rho family identified recently, which consists of two Rho-like genes, Arht1 and Arht2. ARHT may be involved in mitochondrial homeostasis and apoptosis. Constitutively active mutants of ARHT1 induced an aggregation of the mitochondrial network and resulted in an increased apoptotic rate of the cells. Here we report the molecular cloning and characterization of a novel mouse cDNA encoding a putative atypical GTPase protein, Arht2. Mouse Arht2 consists of 19 exons and has been mapped to mouse chromosome 17A3.3. Both human and mouse Arht2 genes are ubiquitously expressed in adult tissues. The results of RT-PCR experiments indicated that the Arht2 gene is expressed in all stages of mouse testis and reached the adult level of transcription at postnatal day 30. In situ hybridization revealed strong hybridization signals of Arht2 in residual bodies. In the mouse testis, Arht2 may be involved in the differentiation of testis and spermiogenesis. The molecular characterization of the mouse Arht2 gene may provide a clue for functional studies of the human ARHT genes.

The Miro GTPases: At the heart of the mitochondrial transport machinery

“…In humans, both Miro1 and Miro2 appear to be universally expressed, demonstrating particularly high expression levels in heart and skeletal muscle tissues [19]. The expression profile analysis of the mouse Miro2 ortholog, ARHT2, showed that ARHT2 is ubiquitously expressed throughout adult tissues, with high expression in heart, testis, skeletal muscle and brain, and lower expression in liver, lung and spleen [28]. The fact that the Miro GTPases are conserved from yeast to human, and are expressed in most cell types, suggest that these proteins have an essential role in organism development and cell survival.…”

EMB2473/MIRO1, anArabidopsisMiro GTPase, Is Required for Embryogenesis and Influences Mitochondrial Morphology in Pollen

“…A novel class of GTPases, the Miro GTPase family, was recently identified in humans (Fransson et al, 2003(Fransson et al, , 2006, mice (Shan et al, 2004), yeast (Frederick et al, 2004), and Drosophila (Guo et al, 2005). They contain two GTPase domains and two calcium binding EF-hand motifs and are associated with the outer mitochondrial membrane via their C-terminal transmembrane domains (TMs) ( Figure 1A).…”