Cys2/His2 zinc-finger protein family of petunia: evolution and general mechanism of target-sequence recognition.

The EPF family is a group of Cys2/His2zinc-finger proteins in petunia. In these proteins, characteristically long spacer regions have been found to separate the zinc fingers. Our previous DNA-binding studies demonstrated that two-fingered proteins (ZPT2-1 and ZPT2-2), which have spacers of different lengths, bind to two separate AGT core motifs in a spacing specific manner. To investigate the possibility that these proteins might distinguish between the target sequences on the basis of spacing between the core motifs, we screened petunia cDNA library for other proteins belonging to this family. Initial screening by PCR and subsequent cloning of full-length cDNAs allowed us to identify the genes for 10 new proteins that had two, three or four zinc fingers. Among the two-fingered proteins the spacing between zinc fingers varied from 19 to 65 amino acids. The variation in the length of spacers was even more extensive in three- and four-fingered proteins. The presence of such proteins is consistent with our hypothesis that the spacing between the core motifs might be important for target sequence recognition. Furthermore, comparison of diverse protein structures suggests that three- and two-fingered proteins might have resulted due to successive loss of fingers from a four-fingered protein during molecular evolution. We also demonstrate that a highly conserved motif (QALGGH) among the members of EPF family and other Cys2/His2 zinc-finger proteins in plants is critical for the DNA-binding activity.     

The ancient source of a distinct gene family encoding proteins featuring RING and C(3)H zinc-finger motifs with abundant expression in developing brain and nervous system

Intronless genes can arise by germline retrotransposition of a cDNA originating as mRNA from an intron-containing source gene. Previously, we described several members of a family of intronless mammalian genes encoding a novel class of zinc-finger proteins, including one that shows imprinted expression and one that escapes X-inactivation. We report here the identification and characterization of the Makorin ring finger protein 1 gene (MKRN1), a highly transcribed, intron-containing source for this family of genes. Phylogenetic analyses clearly indicate that the MKRN1 gene is the ancestral founder of this gene family. We have identified MKRN1 orthologs from human, mouse, wallaby, chicken, fruitfly, and nematode, underscoring the age and conservation of this gene. The MKRN gene family encodes putative ribonucleoproteins with a distinctive array of zinc-finger motifs, including two to four C(3)H zinc-fingers, an unusual Cys/His arrangement that may represent a novel zinc-finger structure, and a highly conserved RING zinc-finger. To date, we have identified nine MKRN family loci distributed throughout the human genome. The human and mouse MKRN1 loci map to a conserved syntenic group near the T-cell receptor beta cluster (TCRB) in chromosome 7q34-q35 and chromosome 6A, respectively. MKRN1 is widely transcribed in mammals, with high levels in murine embryonic nervous system and adult testis. The ancient origin of MKRN1, high degree of conservation, and expression pattern suggest important developmental and functional roles for this gene and its expressed family members.     

水稻受盐抑制基因OsZFP1的转基因分析

OsZFP1(水稻锌指蛋白1)基因编码的蛋白含有3个推测的Cys2/Cys2-型锌指结构域,它的表达受盐胁迫负调控。构建了以35S为启动子的OsZFP1基因的植物表达载体,并将其转入拟南芥(ArabidopsisthalianaL.)植物和水稻(OryzasativaL.)愈伤组织中以过量表达OsZFP1基因。转基因的拟南芥植株和水稻愈伤组织对盐处理的敏感性都比野生型要高。这一结果表明OsZFP1基因可能编码一种负调控蛋白,它可能抑制某些盐诱导基因的表达。在ABA处理下,转基因拟南芥植株比野生型植株抽苔晚,说明OsZFP1基因的作用可能受ABA调节。     

Genome-wide analysis of tomato WIP family genes and their response to salt stress under glutathione treatment

Journal of Plant Biochemistry and Biotechnology - Cys2His2 (C2H2)-type zinc-finger proteins (ZFPs) participate in plant tolerance under various abiotic stresses. Wound-induced protein (WIP) is a...     

A split zinc-finger protein is required for normal yeast growth.

We have identified a gene that, when present in multiple copies, partially inhibits nuclear protein localization in Saccharomyces cerevisiae. This gene encodes a protein that is a unique member of the Cys2His2 zinc-finger family of DNA-binding proteins. It is designated SFP1 for split finger protein because its two zinc-finger domains are separated from one another by 40 amino acids (aa) as opposed to the usual spacing of 7 or 8 aa for Cys2His2 proteins. Disruption of the SFP1 gene results in slow cell growth, with cells having multiple, nucleated buds.