title: Characterization of human Sec16B: indications of specialized, non-redundant functions.
abstract: The endoplasmic reticulum (ER) represents the entry point into the secretory pathway and from here newly synthesized proteins and lipids are delivered to the Golgi. The selective cargo export from the ER is mediated by COPII-assembly at specific sites of the ER, the so-called transitional ER (tER). The peripheral membrane protein Sec16, first identified in yeast, localizes to transitional ER and plays a key role in organization of these sites. Sec16 defines the tER and is thought to act as a scaffold for the COPII coat assembly. In humans two isoforms of Sec16 are present, the larger Sec16A and the smaller Sec16B. Nevertheless, the functional differences between the two isoforms are ill-defined. Here we describe characterization of the localization and dynamics of Sec16B relative to Sec16A, provide evidence that Sec16B is likely a minor or perhaps specialized form of Sec16, and that it is not functionally redundant with Sec16A.
authors.affiliation: Cell Biology Laboratories, School of Biochemistry, University of Bristol, Medical Sciences Building, University Walk, Bristol, BS8 1TD.
authors.forename: Annika
authors.initials: A
authors.lastname: Budnik
authors.forename: Kate J
authors.initials: KJ
authors.lastname: Heesom
authors.forename: David J
authors.initials: DJ
authors.lastname: Stephens
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D016133:Polymerase Chain Reaction; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D034741:RNA, Small Interfering; C443860:SEC16B protein, human; D049452:Green Fluorescent Proteins