KIN241: a gene involved in cell morphogenesis in Paramecium tetraurelia reveals a novel protein family of cyclophilin-RNA interacting proteins (CRIPs) conserved from fission yeast to man

Krzywicka, A Beisson, J Keller, AM Cohen, J Jerka-Dziadosz, M Klotz, C

A. Krzywicka et al., KIN241: a gene involved in cell morphogenesis in Paramecium tetraurelia reveals a novel protein family of cyclophilin-RNA interacting proteins (CRIPs) conserved from fission yeast to man, MOL MICROB, 42(1), 2001, pp. 257-267

49

INGLESE

Article

Microbiology

MOLECULAR MICROBIOLOGY

0950-382X → ACNP

42

1

2001

257 - 267

ISI

0950-382X(200110)42:1<257:KAGIIC>2.0.ZU;2-H

In this study, we report cloning, by functional complementation of the KIN2 41 gene involved in Paramecium cell morphogenesis, cortical organization an d nuclear reorganization. This gene is predicted to encode a protein of a n ovel type, comprising a cyclophilin-type, peptidyl-prolyl isomerase domain, an RNA recognition motif, followed by a region rich in glutamate and lysin e (EK domain) and a C-terminal string of serines. As homologues of this pro tein are present in the genomes of Schizosaccharomyces pombe, Caenorhabditi s elegans, Drosophila melanogaster, Arabidopsis thaliana and Homo sapiens, the Kin241p predicted sequence defines a new family of proteins that we pro pose to call 'CRIP', for cyclophilin-RNA interacting protein. We demonstrat e that, in Paramecium, Kin241p is localized in the nucleus and that deletio n of some nuclear localization signals (NLSs) decreases transport of the pr otein into the nucleus. No Kin241-1 protein is present in mutant cells, sug gesting that the C-terminal serine-rich region is responsible for protein s tability.