title: Tudor-related proteins TDRD1/MTR-1, TDRD6 and TDRD7/TRAP: domain composition, intracellular localization, and function in male germ cells in mice.
abstract: The germ-line cells of many animals possess a characteristic cytoplasmic structure termed nuage or germinal granules. In mice, nuage that is prominent in postnatal male germ cells is also called intermitochondrial cement or chromatoid bodies. TDRD1/MTR-1, which contains Tudor domain repeats, is a specific component of the mouse nuage, analogously to Drosophila Tudor, a constituent of polar granules/nuage in oocytes and embryos. We show that TDRD6 and TDRD7/TRAP, which also contain multiple Tudor domains, specifically localize to nuage and form a ribonucleoprotein complex together with TDRD1/MTR-1. The characteristic co-localization of TDRD1, 6 and 7 was disrupted in a mutant of mouse vasa homologue/DEAD box polypeptide 4 (Mvh/Ddx4), which encodes another evolutionarily conserved component of nuage. In vivo over-expression experiments of the TDRD proteins and truncated forms during male germ cell differentiation showed that a single Tudor domain is a structural unit that localizes or accumulates to nuage, but the expression of the truncated, putative dominant negative forms is detrimental to meiotic spermatocytes. These results indicate that the Tudor-related proteins, which contain multiple repeats of the Tudor domain, constitute an evolutionarily conserved class of nuage components in the germ-line, and their localization or accumulation to nuage is likely conferred by a Tudor domain structure and downstream of Mvh, while the characteristic repeated architecture of the domain is functionally essential for the differentiation of germ cells.
authors.affiliation: Department of Development and Differentiation, Institute for Frontier Medical Sciences, Kyoto University, Shogoin, Kyoto, Japan.
authors.forename: Mihoko
authors.initials: M
authors.lastname: Hosokawa
authors.forename: Masanobu
authors.initials: M
authors.lastname: Shoji
authors.forename: Kouichi
authors.initials: K
authors.lastname: Kitamura
authors.forename: Takashi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Noce
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Chuma
authors.forename: Norio
authors.initials: N
authors.lastname: Nakatsuji
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018797:Cell Cycle Proteins; D017931:DNA Primers; D005455:Fluorescent Antibody Technique; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012261:Ribonucleoproteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017411:Ribonucleoproteins, Small Nuclear / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D017931:DNA Primers; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear; C517521:TDRD6 protein, mouse; C517522:TDRD7 protein, mouse; C488681:Tdrd1 protein, mouse