title: Sperm Associated Antigen 6 (SPAG6) Regulates Fibroblast Cell Growth, Morphology, Migration and Ciliogenesis.
abstract: Mammalian Spag6 is the orthologue of Chlamydomonas PF16, which encodes a protein localized in the axoneme central apparatus, and regulates flagella/cilia motility. Most Spag6-deficient mice are smaller in size than their littermates. Because SPAG6 decorates microtubules, we hypothesized that SPAG6 has other roles related to microtubule function besides regulating flagellar/cilia motility. Mouse embryonic fibroblasts (MEFs) were isolated from Spag6-deficient and wild-type embryos for these studies. Both primary and immortalized Spag6-deficient MEFs proliferated at a much slower rate than the wild-type MEFs, and they had a larger surface area. Re-expression of SPAG6 in the Spag6-deficient MEFs rescued the abnormal cell morphology. Spag6-deficient MEFs were less motile than wild-type MEFs, as shown by both chemotactic analysis and wound-healing assays. Spag6-deficient MEFs also showed reduced adhesion associated with a non-polarized F-actin distribution. Multiple centrosomes were observed in the Spag6-deficient MEF cultures. The percentage of cells with primary cilia was significantly reduced compared to the wild-type MEFs, and some Spag6-deficient MEFs developed multiple cilia. Furthermore, SPAG6 selectively increased expression of acetylated tubulin, a microtubule stability marker. The Spag6-deficient MEFs were more sensitive to paclitaxel, a microtubule stabilizer. Our studies reveal new roles for SPAG6 in modulation of cell morphology, proliferation, migration, and ciliogenesis.
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Abir
authors.initials: A
authors.lastname: Mukherjee
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.|School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei 430065, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Maria E
authors.initials: ME
authors.lastname: Teves
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Hongfei
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Shanti
authors.initials: S
authors.lastname: Nambiar
authors.affiliation: Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Henderson
authors.affiliation: Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA.
authors.forename: Alan R
authors.initials: AR
authors.lastname: Horwitz
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.|Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Jerome F
authors.initials: JF
authors.lastname: Strauss
authors.affiliation: Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Xianjun
authors.initials: X
authors.lastname: Fang
authors.affiliation: Department of Obstetrics &Gynecology, Virginia Commonwealth University, Richmond, VA, 23298.|Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, 23298.
authors.forename: Zhibing
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D019556:COS Cells; D002448:Cell Adhesion / Q000235:genetics; D002465:Cell Movement / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics*; D002470:Cell Survival / Q000235:genetics; D002522:Chlorocebus aethiops; D002923:Cilia / Q000235:genetics* / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D003599:Cytoskeleton / Q000378:metabolism; D004622:Embryo, Mammalian / Q000166:cytology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008868:Microtubule Proteins / Q000235:genetics* / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology; D014404:Tubulin / Q000378:metabolism; D050257:Tubulin Modulators / Q000494:pharmacology
chemical_list: D008868:Microtubule Proteins; C504274:SPAG6 protein, mouse; D014404:Tubulin; D050257:Tubulin Modulators; D017239:Paclitaxel