Identification and characterization of a novel zinc finger protein (HZF1) gene and its function in erythroid and megakaryocytic differentiation of K562 cells

Abstract

A novel zinc finger protein (HZF1) gene was identified and characterized by screening a human bone marrow cDNA library, using a new expression sequence tag probe that contains sequences encoding zinc finger motifs. There are at least three transcripts that may result from different splicing of the pre-mRNA, but the differences among them are only involved in 5 0 non-translation region of HZF1 mRNA. HZF1 gene contains four exons and three introns. The putative protein consists of 670 amino-acid residues including 15 typical C2H2 and 2 C2RH zinc finger motifs. This structure characterization of HZF1 and the nuclear location of the protein suggest that HZF1 may function as a transcription factor. HZF1 mRNA expression was detected in ubiquitous tissues and various hematopoietic cell lines. Increased HZF1 mRNA expression was observed following erythroid differentiation of K562 cells induced by hemin or megakaryocytic differentiation of K562 cells induced by phorbol myristate acetate (PMA). Both of the antisense method and RNA interference assay revealed that repression of the intrinsic expression of HZF1 blocked the hemin-induced erythroid differentiation and reduced the PMA-induced megakaryocytic differentiation of K562 cells, which suggested that HZF1 play important roles in erythroid and megakaryocytic differentiation.

Zinc finger protein HZF1 promotes K562 cell proliferation by interacting with and inhibiting INCA1

“…Primary antibody against HZF1 was raised in rabbit as previously described (7). Additional primary antibodies used for immunoprecipitation or Western blot analysis detection were rabbit polyclonal-pRb (Abcam, UK), mouse monoclonal-Rb (Abcam), mouse monoclonal-c-Myc (Santa Cruz), mouse monoclonal-Flag (Santa Cruz) and mouse monoclonal-GAPDH (Clontech).…”

“…By using an antisense method and a RNA inference assay, we previously showed that repression of the intrinsic expression of HZF1 reduced hemin-induced erythroid differentiation and phorbol myristate acetate (PMA)-induced megakaryocytic differentiation of K562 cells, suggesting its significant role in erythroid and megakaryocytic differentiation (7). The Northern blot assay revealed that HZF1 was extensively expressed in human tissues and cell lines (7), indicating that HZF1 may be involved in the regulation of certain significant cellular functions. In this study, HZF1 overexpression was found to accelerate the proliferation of K562 cells by facilitating the cell cycle phase transition from the S to G2/M phase, and slightly inhibited the apoptosis of K562 cells.…”

“…Previously, we identified and characterized a C 2 H 2 type zinc finger protein gene HZF1 (ZNF16) by screening a human bone marrow cDNA library (7). The full reading frame of the HZF1 gene encodes a 670 amino-acid peptide, and the C-terminal of this peptide contains 17 uninterrupted zinc fingers including 15 typical and 2 atypical C 2 H 2 zinc finger motifs, and TGEKPYE repeats between any two zinc fingers (7).…”

“…Previously, we identified and characterized a C 2 H 2 type zinc finger protein gene HZF1 (ZNF16) by screening a human bone marrow cDNA library (7). The full reading frame of the HZF1 gene encodes a 670 amino-acid peptide, and the C-terminal of this peptide contains 17 uninterrupted zinc fingers including 15 typical and 2 atypical C 2 H 2 zinc finger motifs, and TGEKPYE repeats between any two zinc fingers (7). By using an antisense method and a RNA inference assay, we previously showed that repression of the intrinsic expression of HZF1 reduced hemin-induced erythroid differentiation and phorbol myristate acetate (PMA)-induced megakaryocytic differentiation of K562 cells, suggesting its significant role in erythroid and megakaryocytic differentiation (7).…”

“…The full reading frame of the HZF1 gene encodes a 670 amino-acid peptide, and the C-terminal of this peptide contains 17 uninterrupted zinc fingers including 15 typical and 2 atypical C 2 H 2 zinc finger motifs, and TGEKPYE repeats between any two zinc fingers (7). By using an antisense method and a RNA inference assay, we previously showed that repression of the intrinsic expression of HZF1 reduced hemin-induced erythroid differentiation and phorbol myristate acetate (PMA)-induced megakaryocytic differentiation of K562 cells, suggesting its significant role in erythroid and megakaryocytic differentiation (7). The Northern blot assay revealed that HZF1 was extensively expressed in human tissues and cell lines (7), indicating that HZF1 may be involved in the regulation of certain significant cellular functions.…”