title: A-kinase anchoring protein 4 has a conserved role in mammalian spermatogenesis.
abstract: A-kinase anchor protein 4 (AKAP4) is an X-linked member of the AKAP family of scaffold proteins that anchor cAMP-dependent protein kinases and play an essential role in fibrous sheath assembly during spermatogenesis and flagellar function in spermatozoa. Marsupial spermatozoa differ in structural organization from those of eutherian mammals but data on the molecular control of their structure and function are limited. We therefore cloned and characterized the AKAP4 gene in a marsupial, the tammar wallaby (Macropus eugenii). The gene structure, sequence, and predicted protein of AKAP4 were highly conserved with that of eutherian orthologues and it mapped to the marsupial X-chromosome. There was no AKAP4 expression detected in the developing young. In the adult, AKAP4 expression was limited to the testis with a major transcript of 2.9 kb. AKAP4 mRNA was expressed in the cytoplasm of round and elongated spermatids while its protein was found on the principal piece of the flagellum in the sperm tail. This is consistent with its expression in other mammals. Thus, AKAP4 appears to have a conserved role in spermatogenesis for at least the last 166 million years of mammalian evolution.
authors.affiliation: ARC Centre of Excellence for Kangaroo Genomics, Department of Zoology, The University of Melbourne, Melbourne, Victoria 3010, Australia.
authors.forename: Yanqiu
authors.initials: Y
authors.lastname: Hu
authors.forename: Hongshi
authors.initials: H
authors.lastname: Yu
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pask
authors.forename: Deborah A
authors.initials: DA
authors.lastname: O'Brien
authors.forename: Geoff
authors.initials: G
authors.lastname: Shaw
authors.forename: Marilyn B
authors.initials: MB
authors.lastname: Renfree
mesh_terms: D054758:A Kinase Anchor Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D017124:Conserved Sequence; D007614:Macropodidae / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000378:metabolism; D013082:Sperm Tail / Q000378:metabolism; D013087:Spermatids / Q000378:metabolism; D013091:Spermatogenesis; D013737:Testis / Q000378:metabolism; D014960:X Chromosome
chemical_list: D054758:A Kinase Anchor Proteins; D012333:RNA, Messenger