A comparative study of the involvement of 17 Arabidopsis myosin family members on the motility of Golgi and other organelles.
Gene families with multiple members are predicted to have individuals with overlapping functions. We examined all of the Arabidopsis (Arabidopsis thaliana) myosin family members for their involvement in Golgi and other organelle motility. Truncated fragments of all 17 annotated Arabidopsis myosins containing either the IQ tail or tail domains only were fused to fluorescent markers and coexpressed with a Golgi marker in two different plants. We tracked and calculated Golgi body displacement rate in the presence of all myosin truncations and found that tail fragments of myosins MYA1, MYA2, XI-C, XI-E, XI-I, and XI-K were the best inhibitors of Golgi body movement in the two plants. Tail fragments of myosins XI-B, XI-F, XI-H, and ATM1 had an inhibitory effect on Golgi bodies only in Nicotiana tabacum, while tail fragments of myosins XI-G and ATM2 had a slight effect on Golgi body motility only in Nicotiana benthamiana. The best myosin inhibitors of Golgi body motility were able to arrest mitochondrial movement too. No exclusive colocalization was found between these myosins and Golgi bodies in our system, although the excess of cytosolic signal observed could mask myosin molecules bound to the surface of the organelle. From the preserved actin filaments found in the presence of enhanced green fluorescent protein fusions of truncated myosins and the motility of myosin punctae, we conclude that global arrest of actomyosin-derived cytoplasmic streaming had not occurred. Taken together, our data suggest that the above myosins are involved, directly or indirectly, in the movement of Golgi and mitochondria in plant cells.
Institute of Plant Sciences, Volcani Center, Bet-Dagan 50250, Israel.
Dror
D
Avisar
Mohamad
M
Abu-Abied
Eduard
E
Belausov
Einat
E
Sadot
Chris
C
Hawes
Imogen A
IA
Sparkes
D000199:Actins / Q000378:metabolism; D017360:Arabidopsis / Q000166:cytology / Q000378:metabolism*; D003595:Cytoplasmic Streaming; D006056:Golgi Apparatus / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D009068:Movement; D005810:Multigene Family; D009218:Myosins / Q000737:chemistry / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D019441:Plant Epidermis / Q000166:cytology; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology; D000097573:Red Fluorescent Protein
D000199:Actins; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins; D009218:Myosins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D000097573:Red Fluorescent Protein; C485184:enhanced green fluorescent protein