Novel actin-like proteins T-ACTIN 1 and T-ACTIN 2 are differentially expressed in the cytoplasm and nucleus of mouse haploid germ cells.
We isolated cDNA clones for the novel actin-like proteins T-ACTIN 1 and T-ACTIN 2, which are expressed specifically in the mouse testis. These clones were from a subtracted cDNA library that was enriched for haploid germ cell-specific cDNAs. The mRNA sizes and deduced molecular masses of t-actin 1/mACTl7b and t-actin 2/mACTl7a were 2.2 kilobases (kb) and 1.8 kb, and Mr 43.1 x 10(3) and Mr 47.2 x 10(3), respectively. The two deduced amino acid sequences had 60% homology, and they had approximately 40% homology with other actins. The T-ACTINs contained some of the conserved regions seen in other actins. Although the cellular locations of these two proteins are quite different (T-ACTIN-1 was found in the cytoplasm and T-ACTIN-2 was located in the nucleus), the expression of their proteins and mRNAs is controlled during development and limited during spermiogenesis. In contrast, only T-ACTIN-2 was present in sperm heads and tails. These results suggest that T-ACTINs play important roles in sperm function and in the specific morphogenesis of spermatozoa during spermiogenesis.
Tanaka
Hiromitsu
H
Department of Science for Laboratory Animal Experimentation, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan.
Iguchi
Naoko
N
Egydio de Carvalho
Carlos
C
Tadokoro
Yuko
Y
Yomogida
Kentaro
K
Nishimune
Yoshitake
Y
D000199:Actins / Q000096:biosynthesis* / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002467:Cell Nucleus / Q000235:genetics* / Q000378:metabolism*; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000235:genetics* / Q000378:metabolism*; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D015870:Gene Expression / Q000235:genetics*; D015723:Gene Library; D005854:Germ Cells / Q000378:metabolism*; D006238:Haploidy; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D013091:Spermatogenesis / Q000502:physiology; D013737:Testis / Q000166:cytology / Q000378:metabolism
D000199:Actins; C483118:Actl7a protein, mouse; C480961:Actl7b protein, mouse; D003598:Cytoskeletal Proteins; D018076:DNA, Complementary