title: Alternative splicing of ADAM15 regulates its interactions with cellular SH3 proteins.
abstract: A Disintegrin And Metalloprotease (ADAM15) is a member of the adamalysin protein family and has been associated with cancer, possibly via its role in ectodomain shedding of cadherins. Alternative mRNA splicing generates several ADAM15 isoforms containing different combinations of putative Src homology-3 (SH3) domain binding sites in their cytosolic tails. Here we present a comprehensive characterization of SH3 binding potential of different ADAM15 isoforms. Alternative use of ADAM15 exons was found to profoundly influence selection of SH3-containing cellular partner proteins, including the avid interactions with nephrocystin and sorting nexin-33 (SNX33 a.k.a. SNX30). Specifically, strong co-precipitation of nephrocystin from cell lysates was specific to ADAM15 isoforms i4, i5, and i6. These isoforms contain one or both of the two almost identical proline-rich regions encoded by exons 20 and 21, wherein the residues RxLPxxP were found to be indispensable for nephrocystin SH3 binding. Similarly, robust cellular association with SNX33 was observed only for ADAM15 isoforms containing the most carboxyterminal proline cluster lacking in isoforms i1 and i3. Thus, alternative mRNA splicing provides a versatile mechanism for regulation of intracellular protein interactions and thereby likely the cellular functions of ADAM15, which could explain the association with cancer of some but not all ADAM15 isoforms.
authors.affiliation: Department of Virology, Haartman Institute, Helsinki University Central Hospital, University of Helsinki and HUSLAB, Haartmaninkatu 3, P.O. Box 21, FIN-00014 Helsinki, Finland.
authors.forename: Iivari
authors.initials: I
authors.lastname: Kleino
authors.forename: Rebekka M
authors.initials: RM
authors.lastname: Ortiz
authors.forename: Miljamartta
authors.initials: M
authors.lastname: Yritys
authors.forename: Ari-Pekka J
authors.initials: AP
authors.lastname: Huovila
authors.forename: Kalle
authors.initials: K
authors.lastname: Saksela
mesh_terms: D051722:ADAM Proteins / Q000096:biosynthesis* / Q000235:genetics*; D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry*; D017398:Alternative Splicing; D020816:Amino Acid Motifs; D002352:Carrier Proteins / Q000737:chemistry*; D002460:Cell Line; D003598:Cytoskeletal Proteins; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000737:chemistry* / Q000235:genetics*; D011392:Proline / Q000737:chemistry; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D058305:Sorting Nexins; D033921:Vesicular Transport Proteins / Q000737:chemistry*; D018909:src Homology Domains
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D008565:Membrane Proteins; C108725:NPHP1 protein, human; D020033:Protein Isoforms; D012333:RNA, Messenger; C531049:SNX33 protein, human; D058305:Sorting Nexins; D033921:Vesicular Transport Proteins; D011392:Proline; D051722:ADAM Proteins; C098660:ADAM15 protein, human