Sequence analysis of cDNAs encoding precursors of starfish asterosaps

• Published in: Developmental genetics 1999, Vol.25 (2), p.130-136
• Main Authors: Matsumoto, Midori, Briones, Annabelle V., Nishigaki, Takuya, Hoshi, Motonori
• Format: Article
• Language: English
• Subjects: Acrosome Reaction; Amino Acid Sequence; Animals; Asteroidea; asterosaps; Base Sequence; cDNA cloning; Cloning, Molecular; DNA Primers - genetics; DNA, Complementary - genetics; Female; invertebrate fertilization; Male; Marine; Molecular Sequence Data; Oocytes - metabolism; Ovary - metabolism; Peptides - genetics; precursor; Protein Precursors - genetics; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Homology, Amino Acid; sperm activating peptide; Spermatozoa - metabolism; starfish; Starfish - genetics; Starfish - physiology; starfish sperm activating peptides
• ISSN: 0192-253X; 1520-6408
• DOI: 10.1002/(SICI)1520-6408(1999)25:2<130::AID-DVG7>3.0.CO;2-8

To understand how starfish sperm activating peptides (asterosaps) are synthesized in the ovary, we cloned cDNAs encoding asterosaps and elucidated their nucleotide sequences. The mRNA encoding asterosaps was synthesized only in the oocytes, but not in the follicle cells, and the length was 3.7 kb. The cDNA clones contained multiple isoforms of asterosaps. We assume that asterosap precursors are large prepolypeptide chains with an unusual “rosary‐type” structure made of 10 successive similar stretches of 51–55 residues. Each stretch finishes with a “spacer” of 17–21 residues immediately followed by the sequence of one asterosap isoform. The N‐terminal of this precursor has 19–21 successive glutamine‐rich repeating units. Maturation of the precursor may require endopeptidases that cleave both C‐ and N‐sites of lysine‐arginine. Dev. Genet. 25:130–136, 1999. © 1999 Wiley‐Liss, Inc.