The yeast Ran binding protein 1 (Yrb1p) is a small protein of 23 kDa that i
s highly conserved among eukaryotes, It stimulates the GTPase activity of G
sp1p in the presence of the GTPase activating protein Rna1p, In addition to
its role in nucleocytoplasmic transport of macromolecules, YRB1/RanBP1 cou
ld be involved in the regulation of microtubules structure and dynamics, Si
nce microtubules are tightly associated with morphological changes, me have
been interested to study the role and function of YRB1 in the pathogenic f
ungus Candida albicans, where there is regulated change in cellular morphol
ogy. The gene product of CaYRB1 encodes a 212 amino acid protein displaying
73% homology to the S. cerevisiae homologue, The bacterially expressed gen
e product has an apparent molecular weight of 35.7 kDa, We show that it can
complement a S, cerevisiae YRB1 null mutant and that its mRNA does not app
ear to be regulated in response to conditions inducing morphological change
s in C. albicans. The sequence of C. albicans YRB1 has been deposited in th
e GenBank database under Accession No. AF049868. Copyright (C) 2001 John Wi
ley & Sons, Ltd.