Human Pumilio-2 is expressed in embryonic stem cells and germ cells and interacts with DAZ (Deleted in AZoospermia) and DAZ-Like proteins

Early in development, a part of the embryo is set aside to become the germ cell lineage that will ultimately differentiate to form sperm and eggs and transmit genetic information to the next generation. Men with deletions encompassing the Y-chromosome DAZ genes have few or no germ cells but are otherwise healthy, indicating they harbor specific defects in formation or maintenance of germ cells. A DAZ homolog, DAZL (DAZ-Like), is found in diverse organisms, including humans and is required for germ cell development in males and/or females. We identified proteins that interact with DAZ proteins to better understand their function in human germ cells. Here, we show that PUM2, a human homolog of Pumilio, a protein required to maintain germ line stem cells in Drosophila and Caenorhabditis elegans, forms a stable complex with DAZ through the same functional domain required for RNA binding, protein–protein interactions and rescue of Pumilio mutations in flies. We also show that PUM2 is expressed predominantly in human embryonic stem cells and germ cells and colocalizes with DAZ and DAZL in germ cells. These data implicate PUM2 as a component of conserved cellular machinery that may be required for germ cell development.

[1]  S. Rozen,et al.  Diverse spermatogenic defects in humans caused by Y chromosome deletions encompassing a novel RNA–binding protein gene , 1995, Nature Genetics.

[2]  R. Wharton,et al.  Drosophila Brain Tumor is a translational repressor. , 2001, Genes & development.

[3]  R. Wharton,et al.  Binding of pumilio to maternal hunchback mRNA is required for posterior patterning in drosophila embryos , 1995, Cell.

[4]  D. Page,et al.  Severe oligozoospermia resulting from deletions of azoospermia factor gene on Y chromosome , 1996, The Lancet.

[5]  E. Xu,et al.  A gene family required for human germ cell development evolved from an ancient meiotic gene conserved in metazoans , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[6]  M. L. King,et al.  A critical role for Xdazl, a germ plasm-localized RNA, in the differentiation of primordial germ cells in Xenopus. , 2000, Development.

[7]  E. Salido,et al.  Identification of two novel proteins that interact with germ-cell-specific RNA-binding proteins DAZ and DAZL1. , 2000, Genomics.

[8]  A. V. van Bergen,et al.  Microdeletions in the Y chromosome of infertile men. , 1997, The New England journal of medicine.

[9]  M. Wickens,et al.  A three-hybrid system to detect RNA-protein interactions in vivo. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[10]  L. Brown,et al.  Mouse autosomal homolog of DAZ, a candidate male sterility gene in humans, is expressed in male germ cells before and after puberty. , 1996, Genomics.

[11]  Marvin Wickens,et al.  A PUF family portrait: 3'UTR regulation as a way of life. , 2002, Trends in genetics : TIG.

[12]  M. L. King,et al.  A Xenopus DAZ-like gene encodes an RNA component of germ plasm and is a functional homologue of Drosophila boule. , 1998, Development.

[13]  Xinfu Jiao,et al.  Identification of Target Messenger RNA Substrates for the Murine Deleted in Azoospermia-Like RNA-Binding Protein1 , 2002, Biology of reproduction.

[14]  Masashi Yamada,et al.  Maternal Pumilio acts together with Nanos in germline development in Drosophila embryos , 1999, Nature Cell Biology.

[15]  E. Salido,et al.  Association of the Mouse Infertility Factor DAZL1 with Actively Translating Polyribosomes1 , 2000, Biology of reproduction.

[16]  A. Spradling,et al.  A novel group of pumilio mutations affects the asymmetric division of germline stem cells in the Drosophila ovary. , 1997, Development.

[17]  M. Ruggiu,et al.  In vivo and in vitro analysis of homodimerisation activity of the mouse Dazl1 protein. , 2000, Gene.

[18]  A. Aggarwal,et al.  Structure of Pumilio Reveals Similarity between RNA and Peptide Binding Motifs , 2001, Cell.

[19]  S. Strickland,et al.  Nanos and pumilio establish embryonic polarity in Drosophila by promoting posterior deadenylation of hunchback mRNA. , 1997, Development.

[20]  C. Chubb.  Oligotriche and quaking gene mutations. Phenotypic effects on mouse spermatogenesis and testicular steroidogenesis. , 1992, Journal of andrology.

[21]  A. Renshaw,et al.  DAZ Family Proteins Exist Throughout Male Germ Cell Development and Transit from Nucleus to Cytoplasm at Meiosis in Humans and Mice1 , 2000, Biology of reproduction.

[22]  P. Saunders,et al.  A human DAZ transgene confers partial rescue of the mouse Dazl null phenotype. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[23]  R. Lehmann,et al.  Nanos and Pumilio have critical roles in the development and function of Drosophila germline stem cells. , 1998, Development.

[24]  M. Justice,et al.  The quaking gene product necessary in embryogenesis and myelination combines features of RNA binding and signal transduction proteins , 1996, Nature Genetics.

[25]  R. Wharton,et al.  The Pumilio RNA-binding domain is also a translational regulator. , 1998, Molecular cell.

[26]  Marvin Wickens,et al.  NANOS-3 and FBF proteins physically interact to control the sperm–oocyte switch in Caenorhabditis elegans , 1999, Current Biology.

[27]  P. Zamore,et al.  Crystal structure of a Pumilio homology domain. , 2001, Molecular cell.

[28]  Claude Desjardins,et al.  Cell and molecular biology of the testis , 1993 .

[29]  R. Wharton,et al.  Recruitment of Nanos to hunchback mRNA by Pumilio. , 1999, Genes & development.

[30]  M. Ruggiu,et al.  The mouse Dazla gene encodes a cytoplasmic protein essential for gametogenesis , 1997, Nature.

[31]  D. Dorfman,et al.  Human DAZL1 encodes a candidate fertility factor in women that localizes to the prenatal and postnatal germ cells , 1999 .

[32]  M. Wickens,et al.  A conserved RNA-binding protein controls germline stem cells in Caenorhabditis elegans , 2002, Nature.

[33]  M. Ruggiu,et al.  The RNA-binding specificity of the mouse Dazl protein. , 2001, Nucleic acids research.

[34]  M. Parisi,et al.  The Drosophila pumilio gene encodes two functional protein isoforms that play multiple roles in germline development, gonadogenesis, oogenesis and embryogenesis. , 1999, Genetics.