Molecular cloning of a centrin homolog from Marsilea vestita and evidence for its translational control during spermiogenesis.
Spermiogenesis in the water fern Marsilea vestita is a process that reaches completion 11 h after dry microspores are immersed in an aqueous medium at 20 degrees C. Each microspore produces 32 spermatozoids and each spermatozoid has a coiled cell body and approximately 140 cilia. The spermatids make basal bodies de novo, from a structure known as a blepharoplast. From the onset of development, the spores contain a large quantity of protein and stored mRNA. We have found previously that centrin, a protein involved in the function of microtubule organizing centers and present in association with basal bodies in motile cells, is made in large quantity approximately 4 h after the microspores are placed into liquid medium. In this paper, we show that a centrin cDNA (MvCen1) we isolated from M. vestita closely resembles centrin cDNAs from other eukaryotic organisms. MvCen1, synthesized in Escherichia coli as a GST-fusion protein, reacted with anti-centrin monoclonal antibodies on immunoblots. Northern blot analysis demonstrates that centrin mRNA is present in the dry microspore at the time of imbibition, at levels that remain constant over 10 h of development and are unaffected by treatment of spores with alpha-amanitin. The centrin transcripts, stored in dry microspores, cannot be translated in vitro for at least 30 min after imbibition.
Hart
P E
PE
Department of Cell Biology and Molecular Genetics, University of Maryland, College Park 20742, USA.
Wolniak
S M
SM
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics*; D016825:Chlamydomonas reinhardtii / Q000235:genetics; D002868:Chromosomal Proteins, Non-Histone; D003001:Cloning, Molecular; D018744:DNA, Plant; D018506:Gene Expression Regulation, Plant; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics*; D010944:Plants; D014176:Protein Biosynthesis; D012333:RNA, Messenger; D013091:Spermatogenesis
D002135:Calcium-Binding Proteins; D002868:Chromosomal Proteins, Non-Histone; D018744:DNA, Plant; D010940:Plant Proteins; D012333:RNA, Messenger; C056608:caltractin