title: Molecular cloning and characterization of a human brain-specific gene implicated in neuronal differentiation.
abstract: A 2.5 kb human cDNA clone containing a CAG trinucleotide repeat, designated HB20, was isolated from a human fetal brain library. Northern analysis on multi-tissue blots and various cell lines confirmed that HB20 is specifically expressed in the brain. Its expression is low in two glioma cells, moderate in a neuron precursor cell, NT2, but absent in lymphoma, cervical carcinoma, or colonic carcinoma cells. Significant increase of HB20 mRNA was shown along with retinoic acid-induced terminal differentiation of NT2 cells into neuron cells, hNT. Homology comparison of the predicted HB20 amino acid sequence with the current database revealed that it belongs to a newly recognized protein family composed of nucleosome assembly proteins and SET proto-oncogene, which has been shown to interact specifically with B-type cyclins involved in the control of cell proliferation. Together with the detection of nuclear localization signals and apparent nuclear distribution of expressed protein, HB20 is likely to be a brain-specific nuclear protein, functioning in the process of neuronal differentiation.
authors.affiliation: Department of Medicine, Veterans General Hospital-Taipei, Taiwan.
authors.forename: F S
authors.initials: FS
authors.lastname: Fan
authors.forename: H H
authors.initials: HH
authors.lastname: Shen
authors.forename: W P
authors.initials: WP
authors.lastname: Tseng
authors.forename: P M
authors.initials: PM
authors.lastname: Chen
authors.forename: S F
authors.initials: SF
authors.lastname: Tsai
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001923:Brain Chemistry / Q000235:genetics*; D018797:Cell Cycle Proteins; D002454:Cell Differentiation / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone; D018076:DNA, Complementary / Q000032:analysis / Q000302:isolation & purification; D004268:DNA-Binding Proteins; D005333:Fetus; D015870:Gene Expression; D056488:Histone Chaperones; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics*; D009474:Neurons / Q000737:chemistry / Q000166:cytology*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics; D056490:Nucleosome Assembly Protein 1; D009707:Nucleosomes / Q000235:genetics; D009928:Organ Specificity / Q000235:genetics; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000737:chemistry / Q000235:genetics; D000090063:Proto-Oncogene Mas; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors; D018911:Trinucleotide Repeats / Q000235:genetics; D014407:Tumor Cells, Cultured
chemical_list: D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D056488:Histone Chaperones; C000715470:MAS1 protein, human; C533557:NAP1L1 protein, human; C112325:NAP1L3 protein, human; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D056490:Nucleosome Assembly Protein 1; D009707:Nucleosomes; D011506:Proteins; D000090063:Proto-Oncogene Mas; C513473:SET protein, human; D014157:Transcription Factors