title: Algal-CAMs: isoforms of a cell adhesion molecule in embryos of the alga Volvox with homology to Drosophila fasciclin I.
abstract: Proof that plants possess homologs of animal adhesion proteins is lacking. In this paper we describe the generation of monoclonal antibodies that interfere with cell-cell contacts in the 4-cell embryo of the multicellular alga Volvox carteri, resulting in a hole between the cells. The number of following cell divisions is reduced and the cell division pattern is altered drastically. Antibodies given at a later stage of embryogenesis specifically inhibit inversion of the embryo, a morphogenetic movement that turns the embryo inside out. Immunofluorescence microscopy localizes the antigen (Algal-CAM) at cell contact sites of the developing embryo. Algal-CAM is a protein with a three-domain structure: an N-terminal extensin-like domain characteristic for plant cell walls and two repeats with homology to fasciclin I, a cell adhesion molecule involved in the neuronal development of Drosophila. Alternatively spliced variants of Algal-CAM mRNA were detected that are produced under developmental control. Thus, Algal-CAM is the first plant homolog of animal adhesion proteins.
authors.affiliation: Lehrstuhl Biochemie I, Universität Regensburg, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Huber
authors.forename: M
authors.initials: M
authors.lastname: Sumper
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics; D002451:Cell Compartmentation; D000460:Chlorophyta / Q000235:genetics* / Q000254:growth & development / Q000276:immunology; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D004330:Drosophila / Q000235:genetics; D005455:Fluorescent Antibody Technique; D008969:Molecular Sequence Data; D011487:Protein Conformation; D012333:RNA, Messenger / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid
chemical_list: D000911:Antibodies, Monoclonal; D015815:Cell Adhesion Molecules; D015816:Cell Adhesion Molecules, Neuronal; D018076:DNA, Complementary; D012333:RNA, Messenger; C051641:fasciclin I