Evolutionary conservancy of the endocytic and trafficking machinery in the unicellular eukaryote <i>Paramecium</i>

Surmacz, Liliana; Wiejak, Jolanta; Wyroba, Elżbieta

doi:10.1016/s0248-4900(03)00012-1

Cited by 15 publications

(14 citation statements)

References 46 publications

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“…Interestingly, it is proposed that myosin VI isoforms may also play a similar role in controlling the dynamics of actin cytoskeleton [Frank et al, 2004]. Based on the data gathered on vertebrate dynamins and myosin VI as well as the fact that dynamins are one of the most evolutionary (both in structure and function) conserved proteins [Surmacz et al, 2003], we aimed at the confirmation of the presence of dynamin immunoanalog(s) in A. proteus, and used commercially available antibodies against this protein(s) to probe the function of myosin VI immunoanalog in migrating and pinocytotic amoebae. We have shown that dynamin II (but not neuronal dynamin I) immunoanalog was expressed in A. proteus and cosedimented with actin filaments together with myosin VI immunoanalog as well as colocalized with actin and myosin VI containing vesicular structures in vivo.…”

Section: Discussionmentioning

confidence: 99%

“…In order to test a potential function(s) of the myosin VI immunoanalog, its association with dynamins, proteins commonly used as endocytosis markers both in vertebrates [Robinson et al, 1998;Schafer, 2004] and protozoans [Surmacz et al, 2003], was tested. The presence of amoeboid immunoanalog of dynamin II (but not of neuronal dynamin I) was confirmed by probing Amoeba proteus HSS with the relevant monoclonal antibodies (Fig.…”

Section: Cosedimentation Of Myosin VI and Dynamin Ii Immunoanalogs Wimentioning

confidence: 99%

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Characterization of Amoeba proteus myosin VI immunoanalog

Dominik

Kłopocka

Pomorski

et al. 2005

Cell Motil. Cytoskeleton

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Amoeba proteus, the highly motile free-living unicellular organism, has been widely used as a model to study cell motility. However, molecular mechanisms underlying its unique locomotion and intracellular actin-based-only trafficking remain poorly understood. A search for myosin motors responsible for vesicular transport in these giant cells resulted in detection of 130-kDa protein interacting with several polyclonal antibodies against different tail regions of human and chicken myosin VI. This protein was binding to actin in the ATP-dependent manner, and immunoprecipitated with anti-myosin VI antibodies. In order to characterize its possible functions in vivo, its cellular distribution and colocalization with actin filaments and dynamin II during migration and pinocytosis were examined. In migrating amoebae, myosin VI immunoanalog localized to vesicular structures, particularly within the perinuclear and sub-plasma membrane areas, and colocalized with dynamin II immunoanalog and actin filaments. The colocalization was even more evident in pinocytotic cells as proteins concentrated within pinocytotic pseudopodia. Moreover, dynamin II and myosin VI immunoanalogs cosedimented with actin filaments, and were found on the same isolated vesicles. Blocking endogenous myosin VI immunoanalog with anti-myosin VI antibodies inhibited the rate of pseudopodia protrusion (about 19% decrease) and uroidal retraction (about 28% decrease) but did not affect cell morphology and the manner of cell migration. Treatment with anti-human dynamin II antibodies led to changes in directionality of amebae migration and affected the rate of only uroidal translocation (about 30% inhibition). These results indicate that myosin VI immunoanalog is expressed in protist Amoeba proteus and may be involved in vesicle translocation and cell locomotion.

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Section: Discussionmentioning

confidence: 99%

Section: Cosedimentation Of Myosin VI and Dynamin Ii Immunoanalogs Wimentioning

confidence: 99%

Characterization of Amoeba proteus myosin VI immunoanalog

Dominik

Kłopocka

Pomorski

et al. 2005

Cell Motil. Cytoskeleton

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“…Furthermore a fraction of GABA B receptors seemed to be For rab4 and rab11 proteins, sequences are cloned from Paramecium (International Paramecium genomic project, Dessen et al, 2001). Also rab7, a positive regulator of homotypic fusion between late endosomes, was cloned and sequenced in Paramecium and revealed 79% identity to N-terminal region of human rab7 (Surmacz et al, 2003). The confocal laser scanning microscopy revealed its immunoanalogue localized to the phagosomal membrane (Surmacz et al, 2003).…”

Section: Discussionmentioning

confidence: 99%

“…Also rab7, a positive regulator of homotypic fusion between late endosomes, was cloned and sequenced in Paramecium and revealed 79% identity to N-terminal region of human rab7 (Surmacz et al, 2003). The confocal laser scanning microscopy revealed its immunoanalogue localized to the phagosomal membrane (Surmacz et al, 2003). Therefore, plasma membrane components are internalized by endosomes, which are first localized in the cortical region of the cell, transported in the most internal cytoplasmic portion, and fused with other endosomal compartments until their content is transferred to the phagosomes (Ramoino et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

GABAB receptor intracellular trafficking after internalization inParamecium

Ramoino

Usai²,

Beltrame

et al. 2005

Microsc. Res. Tech.

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The number of neurotransmitter receptors on the plasma membrane is regulated by the traffic of intracellular vesicles. Golgi-derived vesicles provide newly synthesized receptors to the cell surface, whereas clathrin-coated vesicles are the initial vehicles for sequestration of surface receptors, which are ultimately degraded or recycled. We have previously shown that GABAB receptors display a punctuate vesicular pattern dispersed on the cell surface and throughout the cytoplasm and are internalized via clathrin-dependent and -independent endocytosis. Here we have studied constitutive GABAB receptor trafficking after internalization in Paramecium primaurelia by confocal laser scanning microscopy and multiple immunofluorescence analysis. After internalization, receptors are targeted to the early endosomes characterized by the molecular markers EEA1 and rab5. Some of these receptors, destined for recycling back to the plasma membrane, traffic from the early endosomes to the endosomal recycling compartment that is characterized by the presence of rab4-immunoreactivity (IR). Receptors that are destined for degradation exit the endosomal pathway at the early endosomes and traffic to the late endosome-lysosome pathway. In fact, some of the GABAB-positive compartments were identified as lysosomal structures by double staining with the lysosomal marker LAMP-1. GABAB vesicle structures also colocalize with TGN38-IR and rab11-IR. TGN38 and rab11 are proteins found in association with post-Golgi and recycling endosomes, respectively.

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“…We have recently cloned the N-terminal and middle domains (1091 nucleotides encoding 363 amino acids) of dynamin in Paramecium. This protein is essential in different endocytic processes (Damke et al, 1994;Schmid et al, 1998;Wiejak et al, 2003) and we showed the presence of the dynamin immunoanalogue localized to the transferrincontaining endosomes Surmacz et al, 2003). Therefore, to elucidate whether receptor sequestration in Paramecium follows a pathway similar to that observed in mammalian cells, we performed experiments with antibodies directed against the C termini of human β 2AR and human dynamin 2.…”

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confidence: 99%

Dynamin-association with agonist-mediated sequestration of beta-adrenergic receptor in single-cell eukaryoteParamecium

Wiejak

Surmacz

Wyroba

2004

Journal of Experimental Biology

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Generallyreceptor sequestration follows its desensitization, which is initiated by receptor phosphorylation by G-protein-coupled receptor kinase. We cloned and sequenced the gene fragment of 407 nucleotides homologous to the β-adrenergic receptor kinase (βARK): its deduced amino acid sequence shows 51.6% homology in 126 amino acids that overlap with the human βARK2 (GRK3), and may participate in Paramecium βAR desensitization.These results suggest that the molecular machinery for the desensitization/sequestration of the receptor immunorelated to vertebrate βAR exists in unicellular Paramecium.

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Evolutionary conservancy of the endocytic and trafficking machinery in the unicellular eukaryote Paramecium

Cited by 15 publications

References 46 publications

Characterization of Amoeba proteus myosin VI immunoanalog

Characterization of Amoeba proteus myosin VI immunoanalog

GABAB receptor intracellular trafficking after internalization inParamecium

Dynamin-association with agonist-mediated sequestration of beta-adrenergic receptor in single-cell eukaryoteParamecium

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