Zinc finger protein gene complexes on mouse chromosomes 8 and 11

Two murine homologs of the Drosophila Krüppel gene, a member of the gap class of developmental control genes that encode a protein with zinc fingers, were mapped to mouse chromosomes 8 and 11 by using somatic cell hybrids and an interspecific backcross. Surprisingly, both genes were closely linked to two previously mapped, Krüppel-related zinc finger protein genes, suggesting that they are part of gene complexes.     

Chromosomal localization of two human zinc finger protein genes, ZNF24 (KOX17) and ZNF29 (KOX26), to 18q12 and 17p13-p12, respectively

Two members of the zinc finger Krüppel family, ZNF24 (KOX17) and ZNF29 (KOX26), have been localized by somatic cell hybrid analysis and in situ chromosomal hybridization to human chromosomes 18q12 and 17p13-p12, respectively. The mapping of ZNF29 together with the previously reported localization of ZFP3 suggests that a zinc finger gene complex is located on human chromosome 17p. ZNF29 maps centromeric to the human p53 tumor antigen gene (TP53). In the analogous murine position, the two mouse zinc finger genes Zfp2 and Zfp3 have recently been assigned to the distal region of mouse chromosome 11, the murine homolog of human chromosome 17. Both human zinc finger genes ZNF24 and ZNF29 are in chromosomal regions that have been noted to be deleted in neoplasms of the lung and of the central nervous system at chromosome 17p and in colorectal neoplasia at chromosomes 17p and 18q.     

A search for a mammalian homologue of the Drosophila photoreceptor development gene glass yields Zfp64, a zinc finger encoding gene which maps to the distal end of mouse chromosome 2

Whilst searching for a mammalian homologue of the Drosophila glass gene we cloned a mouse cDNA whose deduced sequence encodes a 614 amino acid (aa) protein with ten Cys2-His2 (C2H2) zinc finger (Zf) motifs. Zfp64 is expressed in all developing and mature mouse tissues examined, except the mouse erythroleukemia (MEL) cell line. Zfp64 maps to the distal region of mouse chromosome 2 close to lens opacity 4 (Lop4), a semidominant cataract mutation. Sequence analysis shows that Zfp64 has multiple potential phosphorylation sites for casein kinase II (CK II), protein kinase C (PKC), tyrosine kinase (TK) and c-AMP- and c-GMP-dependent protein kinase (cA/GMPDPK).     

Expression of a mouse zinc finger protein gene in both spermatocytes and oocytes during meiosis.

In order to identify genes regulating meiosis, a mouse spermatocyte cDNA library was screened for sequences encoding proteins with C2H2-type zinc finger motifs which are typically expressed by the Drosophila Krüppel gene. Three new cDNAs were isolated, and they were designated CTfin33, CTfin51, and CTfin92. Among them, CTfin51 was selected for further study. The deduced amino acid sequence revealed seven zinc finger motifs in its C-terminal region. Northern blot and in situ hybridization showed CTfin51 mRNA expression in spermatocytes after the pachytene stage and in early stage round spermatids of prepuberal and adult males. Immunocytochemical staining with an antiserum against beta-gal-CTfin51 fusion protein was localized within nuclei of spermatocytes and spermatids. Oocyte nuclei after the pachytene stage also were immunoreactive for CTfin51 protein. Immunoblots revealed a band at M(r) 75,000 in protein extracts from the testis and the ovary. These results suggest that the CTfin51 gene encodes a DNA-binding regulatory protein functionally associated with meiosis in both male and female gametogenesis.     

Localization of the human KRAB finger gene ZNF117 (HPF9) to chromosome 7q11.2.

A cluster of Krüppel type zinc finger genes of the KRAB subclass has recently been localized on human chromosome 19p12-p13.1. We now report that ZNF117 (HPF9), a closely related zinc finger gene of this KRAB subfamily, has been assigned to a distinct locus in the human genome: chromosome band 7q11.2.     

Isolation, characterization, and mapping of a novel human KRAB zinc finger protein encoding gene ZNF463

A novel human KRAB (Krüppel associated box) type zinc finger protein encoding gene, ZNF463, was obtained by mRNA differential display and RACE. It consists of 1904 nucleotides and encodes a protein of 463 amino acids with an amino-terminal KRAB domain and 12 carboxy-terminal C2H2 zinc finger units. The gene is mapped to chromosome 19q13.3 approximately 4 by FISH. As from Northern blot analysis ZNF463 is only expressed in testis, RT-PCR indicates that ZNF463 is expressed more highly in normal fertile adults than in fetus and azoospermic patients suggesting that it may play a role in human spermatogenesis.     

Cloning and characterization of a novel human gene encoding a zinc finger protein with 25 fingers

This study reports cloning and characterization of a human cDNA encoding a novel human zinc finger protein, ZFD25. ZFD25 cDNA is 6118 bp long and has an open reading frame of 2352 bp that encodes a 783 amino acid protein with 25 C2H2-type zinc fingers. The ZFD25 cDNA also contains a region with high sequence similarity to the Krüppel-associated box A and B domain in the 5'-untranslated region, suggesting that ZFD25 belongs to the Krüppel-associated box zinc finger protein family. The ZFD25 gene was localized to chromosome 7q11.2. Northern blot analysis showed that ZFD25 was expressed in a wide range of human organs. In cultured endothelial cells, the mRNA level was decreased upon serum starvation.     

A Kruppel zinc finger of ZNF 146 interacts with the SUMO-1 conjugating enzyme UBC9 and is sumoylated in vivo

The OZF (ZNF146) protein is a 33 kDa Kruppel protein, composed solely of 10 zinc finger motifs. It is overexpressed in the majority of pancreatic cancers and in more than 80% of colorectal cancers. We have identified OZF interacting factors with a yeast two-hybrid screen. Half of the positive clones characterized encoded UBC9, the E2 enzyme involved in the covalent conjugation of the small ubiquitin-like modifier 1 (SUMO-1). SUMO-1 is a 17 kDa migrating protein that is conjugated to several proteins and has been reported to exhibit multiple effects, including modulation of protein stability, subcellular localization, and gene expression. In HeLa cells transfected with OZF and SUMO-1 expression vectors, immunoblot revealed a major band migrating at 50 kDa and a minor band at 67 kDa, corresponding to the attachment to OZF of one and two SUMO-1 proteins, respectively. The relative amount of the sumoylated proteins increased following transfection with a UBC9 expression vector. The presence of the sumoylated form in HeLa cells solely transfected by OZF indicates the physiological activity of the endogenous SUMO-1 conjugation pathway. Using deletion mutants, we showed that two SUMO-1 modification sites are located on the sixth zinc finger. Mutation of two lysine residues greatly reduced the amount of the sumoylated form of OZF though their surrounding sequences differ from the consensus sequence reported for most proteins modified by SUMO-1 conjugation. Despite the presence of the sixth zinc finger, an OZF mutant containing zinc fingers 1–6 was not modified by SUMO-1 and failed to interact with UBC9. Addition of zinc finger 7 restored SUMO-1 modification and UBC9 interaction and provides evidence that a region downstream of the target lysines is required for interaction with UBC9, in order to achieve SUMO-1 modification. This is the first report of in vivo conjugation of a SUMO-1 protein to a Kruppel zinc finger motif. (Mol Cell Biochem 271: 215–223, 2005)     

A gene that encodes a protein consisting solely of zinc finger domains is preferentially expressed in transformed mouse cells.

We describe the cloning and characterization of the mouse MOK-2 gene, a new member of the Krüppel family of zinc finger proteins. Sequencing of both cDNA and genomic clones showed that the predicted MOK-2 protein consists of seven zinc finger domains with only five additional amino acids. The finger domains of MOK-2 are highly homologous to one another but not to those of other zinc finger proteins. MOK-2 is preferentially expressed in transformed cell lines, brain tissue, and testis tissue. Its possible role in cellular transformation is discussed.     

Expression of the transcription factor Zfp191 during embryonic development in the mouse

The human zinc finger protein 191 (ZNF191) is a Krüppel-like protein and can specifically interact with the widespread TCAT motif which constitutes the HUMTH01 microsatellite in the tyrosine hydroxylase (TH) gene (encoding the rate-limiting enzyme in the synthesis of catecholamines). Allelic variations of HUMTH01 are known to have a quantitative silencing effect on TH gene expression and to correlate with quantitative and qualitative changes in the binding by ZNF191. This factor has been isolated from bone marrow and promyelocytic leukemia cell lines indicating that ZNF191 also plays a role in hematopoiesis. Thus, ZNF191 could participate in the regulation of several genes implicated in different functions. Moreover, mice that are deficient in Zfp191, the murine homologue of ZNF191, have been shown to be severely retarded in development and to die approximately at embryonic day 7.5. In order to gain further insight into its biological functions, we have analysed the localisation of Zfp191 throughout mouse development. Expression was detected early during embryogenesis in ectodermal, endodermal, mesodermal and extra-embryonic tissues. In particular, Zfp191 was observed in the developing central nervous system. Interestingly, its expression levels were prominent in areas of proliferation such as the subventricular zone. Zfp191 expression pattern during development can account for the phenotypic features of Zfp191(-/-) embryos.     

Targeted Expression of the only Zinc Finger Gene in Transgenic Mice is Associated with Impaired Mammary Development

The only zinc finger (OZF) gene encodes a protein consisting mainly of 10 zinc finger motifs of the Krüppel type of yet unknown function. To potentially assess its in vivo role, mammary targeted deregulation of the expression of the murine gene was performed in transgenic mice using a goat -casein-based transgene. Mammary expression of the transgene was observed in the 11 lines obtained. In three expressing lines, this expression was tissue-specific and developmentally regulated. Further analysis of mice from two expressing lines revealed that transgene-homozygous females could not sustain full growth of their pups. This phenotype was associated with an impaired mammary gland development noticeable only after mid-gestation. It was characterised by an increase of the adipocyte to acini ratio and low or absence of fat globules within these acini compared to non-transgenic control animals. These transgenic observations strongly suggest that OZF is active in the mammary gland, interfering with the lactation process and thus that the described transgenic mice could be useful models to search for the cellular partner(s) of this protein.