XL43 AND XL75 - 2 NOVEL RING FINGER-CONTAINING GENES EXPRESSED DURINGOOGENESIS AND EMBRYOGENESIS IN XENOPUS-LAEVIS

This article reports on the isolation of two new Xenopus genes that en code two putative zinc finger proteins. The XL43 and XL75 proteins bel ong to the RBCC family, and also contains the rfp-like domain. XL43 an d XL75 RNAs are found in the ovary, and myc-tagged proteins are detect ed in mRNA injected oocytes. Whole-mount in situ hybridization of embr yos revealed that these two clones are expressed exclusively in neurec todermic and mesodermic tissues. The data suggest that XL43 and XL75 g enes could play an important role in the frog's early development, per haps as a transcription factor. This RBCC family, a subclass of the RI NG finger family, comprises proteins with known cellular transformatio n properties. All members possess, besides one RING finger motif, one or two B-boxes, each having a pair of zinc fingers, and a coiled coil domain (Borden, K.L.B. et al., 1996. Proc. Natl. Acad. Sci. USA 93, 16 01-1606). Among this group, some members possess, besides the RING-B b ox-coiled coil (RBCC) motifs, a long C-terminal domain referred to as the rfp-like domain. Although its effective role has not been elucidat ed yet, this last domain could play an important role by binding a lig and (Bellini, M. et al., 1993. EMBO J. 12, 107-114). (C) 1998 Elsevier Science B.V.