Fission yeast syt22 protein, a putative Arf guanine nucleotide  exchange factor, is necessary for new end take off.
In fission yeast Schizosaccharomyces pombe, the directions of cell growth change from monopolar to bipolar in character, which is known as 'new end take off ' (NETO). We previously found that arf6p, a member (class III) of the ADP-ribosylation factor (Arf) family, is necessary for NETO in fission yeast. Here we report the characterization of an S. pombe gene, syt22(+), encoding a putative Arf guanine nucleotide exchange factor (GEF). The syt22 protein contains a Sec7 domain and a PH domain conserved in the mammalian EFA6 GEF family, and has high similarity to Yel1p, which was identified as a GEF for Arf3p (class III Arf) in Saccharomyces cerevisiae. syt22Delta cells, like arf6Delta cells, completely failed to undergo NETO. Syt22p uniformly localizes to the cell periphery. Its localization is not dependent on microtubules, actin cytoskeletons or arf6p. We hypothesize that syt22p functions as a GEF for arf6p.
Atsushi
A
Fujita
Yoshio
Y
Misumi
D020727:ADP-Ribosylation Factors / Q000737:chemistry / Q000502:physiology*; D000199:Actins / Q000648:ultrastructure; D000595:Amino Acid Sequence; D048708:Cell Growth Processes; D016764:Cell Polarity; D005656:Fungal Proteins / Q000502:physiology*; D049452:Green Fluorescent Proteins; D008870:Microtubules / Q000648:ultrastructure; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012568:Schizosaccharomyces; D020539:Sequence Analysis, Protein
D000199:Actins; D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D020727:ADP-Ribosylation Factors