NgUNC-119, Naegleria homologue of UNC-119, localizes to the flagellar rootlet.
The UNC-119 family of proteins is ubiquitous in animals. The expression of UNC-119 is prominent in neural tissues including photoreceptor cells. Homologues of UNC-119 are also found in ciliated (or flagellated) single-celled organisms; however, the cellular distribution of this protein in protists is unknown. We cloned and characterized a homologue of unc-119 from the ameboflagellate Naegleria gruberi (Ngunc-119) and identified the cellular distribution of the protein. The Ngunc-119 open reading frame contained 570 nucleotides encoding a protein of 189 amino acids with a predicted molecular weight of 22.1 kDa, which is similar to that of Paramecium UNC-119 and Trypanosoma UNC-119. These three proteins are 46-48% identical in their amino acid sequences. The smaller NgUNC-119 corresponds to the conserved C-terminal 3/4 of the UNC-119 from multi-cellular organisms. The amino acid sequence of NgUNC-119 is 43-50% identical to that of the conserved C-terminal regions. NgUNC-119 was not found in growing amoebae but accumulated rapidly after the initiation of differentiation into flagellates. Indirect immunofluorescence staining of differentiating N. gruberi showed that NgUNC-119 begins to concentrate at a spot near the nucleus of differentiating cells and then elongates into a filamentous structure. Purification and indirect immunofluorescence staining of the Naegleria flagellar rootlet suggested that NgUNC-119 is a component of the flagellar rootlet.
Chung
Sunglan
S
Department of Biology and the Institute of Life Science and Biotechnology, College of Science, Yonsei University, Seoul 120-749, Republic of Korea.
Kang
Seungmin
S
Paik
Soonyoung
S
Lee
Joohun
J
D000595:Amino Acid Sequence; D000818:Animals; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry; D005407:Flagella / Q000378:metabolism*; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D009253:Naegleria / Q000166:cytology / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000737:chemistry; D021381:Protein Transport; D015800:Protozoan Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017385:Sequence Homology
D029742:Caenorhabditis elegans Proteins; D009419:Nerve Tissue Proteins; D015800:Protozoan Proteins; C098176:UNC-119 protein, C elegans