title: Zebrafish class 1 phosphatidylinositol transfer proteins: PITPbeta and double cone cell outer segment integrity in retina.
abstract: Phosphatidylinositol transfer proteins (PITPs) in yeast co-ordinate lipid metabolism with the activities of specific membrane trafficking pathways. The structurally unrelated metazoan PITPs (mPITPs), on the other hand, are an under-investigated class of proteins. It remains unclear what biological activities mPITPs discharge, and the mechanisms by which these proteins function are also not understood. The soluble class 1 mPITPs include the PITPalpha and PITPbeta isoforms. Of these, the beta-isoforms are particularly poorly characterized. Herein, we report the use of zebrafish as a model vertebrate for the study of class 1 mPITP biological function. Zebrafish express PITPalpha and PITPbeta-isoforms (Pitpna and Pitpnb, respectively) and a novel PITPbeta-like isoform (Pitpng). Pitpnb expression is particularly robust in double cone cells of the zebrafish retina. Morpholino-mediated protein knockdown experiments demonstrate Pitpnb activity is primarily required for biogenesis/maintenance of the double cone photoreceptor cell outer segments in the developing retina. By contrast, Pitpna activity is essential for successful navigation of early developmental programs. This study reports the initial description of the zebrafish class 1 mPITP family, and the first analysis of PITPbeta function in a vertebrate.
authors.affiliation: Department of Cell & Developmental Biology, Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
authors.forename: Kristina E
authors.initials: KE
authors.lastname: Ile
authors.forename: Sean
authors.initials: S
authors.lastname: Kassen
authors.forename: Canhong
authors.initials: C
authors.lastname: Cao
authors.forename: Thomas
authors.initials: T
authors.lastname: Vihtehlic
authors.forename: Sweety D
authors.initials: SD
authors.lastname: Shah
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Mousley
authors.forename: James G
authors.initials: JG
authors.lastname: Alb
authors.forename: Richard P H
authors.initials: RP
authors.lastname: Huijbregts
authors.forename: George W
authors.initials: GW
authors.lastname: Stearns
authors.forename: Susan E
authors.initials: SE
authors.lastname: Brockerhoff
authors.forename: David R
authors.initials: DR
authors.lastname: Hyde
authors.forename: Vytas A
authors.initials: VA
authors.lastname: Bankaitis
mesh_terms: D000818:Animals; D023421:Models, Animal; D049294:Phospholipid Transfer Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D020033:Protein Isoforms; D055214:Retinal Photoreceptor Cell Outer Segment / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D015027:Zebrafish
chemical_list: D049294:Phospholipid Transfer Proteins; D020033:Protein Isoforms