Individual domains of Tensin2 exhibit distinct subcellular localisations and migratory effects.
Tensins are large intracellular proteins believed to link the extracellular matrix to the cytoskeleton via integrins. Tensins are multidomain proteins consisting of homologous C1, PTPase, C2, SH2 and PTB domains. Full-length Tensin proteins can undergo cleavage inside cells, thus yielding domains in isolation that may have discrete subcellular localisations and downstream effects. We expressed different isoforms of Tensin2 and their individual domains as recombinant green fluorescent protein (GFP)-fusion constructs in DU145 human prostate cancer cells. Under fluorescence confocal microscopy, the isolated domains of Tensin2 all displayed discrete distributions throughout the cytoplasm and the nucleus. In particular, partial constructs containing the C1 domain localised preferentially to the nucleus, including the isolated C1 domain and the PTPase domain. In contrast, all three full-length isoforms of Tensin2 were present exclusively in discrete punctate bodies throughout the cytoplasm. This punctate staining showed colocalisation with the tumour suppressor protein DLC-1 as well as with actin (phalloidin). Furthermore, DU145 cells transiently expressing partial Tensin2 constructs containing the PTB domain showed an increased haptotactic migration. In addition, stimulation of renal carcinoma cells stably expressing Tensin2 by the survival factor Gas6 caused phosphorylation of its receptor Axl, but no effect on Tensin2, which was already maximally phosphorylated at time 0. In conclusion, our results indicate that differential proteolytic cleavage of Tensin2 can liberate domains with discrete localisations and functions, which has implications for the role of Tensins in cancer cell survival and motility.
Hafizi
Sassan
S
Lund University, Department of Laboratory Medicine, Section for Clinical Chemistry, University Hospital Malmö, SE-205 02 Malmö, Sweden. sassan.hafizi@port.ac.uk
Sernstad
Emma
E
Swinny
Jerome D
JD
Gomez
Maria F
MF
Dahlbäck
Björn
B
D002451:Cell Compartmentation / Q000187:drug effects; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D020690:GTPase-Activating Proteins; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000494:pharmacology; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D008840:Microfilament Proteins / Q000737:chemistry* / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D019000:Phosphotyrosine / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021381:Protein Transport / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism*; D000070876:Tensins; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D000099255:Growth Arrest-Specific Protein 6
D020690:GTPase-Activating Proteins; D049452:Green Fluorescent Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008840:Microfilament Proteins; D010744:Phosphoric Monoester Hydrolases; D019000:Phosphotyrosine; D011993:Recombinant Fusion Proteins; D000070876:Tensins; D025521:Tumor Suppressor Proteins; D000099255:Growth Arrest-Specific Protein 6; C112352:DLC1 protein, human; C452816:TNS2 protein, human