Fig. 1. Sbf1 is a unique member of the myotubularin family of phosphatases. (A)
Schematic representation of Sbf1 and myotubularin-related proteins. A highly
conserved region that spans the PTP consensus motif is indicated by black
rectangles; PTP motifs containing germline mutations are indicated with half
white/half black rectangles. Gray oval in Sbf1 indicates CRS domain conserved
in various signaling proteins. Gray box at Sbf1 N terminus denotes 80 amino
acids of additional similarity with the N terminus of Rab3GEF. Start and stop
codons are indicated in proteins where they are known. (B) Sequence alignment
of the N-terminal CRS domain in Sbf1 reveals similarity with several known and
hypothetical proteins. Black boxes indicate identical residues; shaded boxes
indicate conservative amino acid substitutions. AA481292, AL161790 and
AI158686 are unique human or mouse ESTs. C12714 is a predicted C.
elegans protein. Sequences for CRAG, ST5, Rab3GEF, Rab6BP have been
reported previously (Xu et al.,
1998; Janoueix-Lerosey et al.,
1995; Wada et al.,
1997). (C) Anti-Sbf1 western
blot analysis of NIH 3T3 cells stably transfected with wild-type Sbf1 or
vector alone.
