TY - JOUR
T1 - Synaptojanin 1
T2 - Localization on coated endocytic intermediates in nerve terminals and interaction of its 170 kDa isoform with Eps15
AU - Haffner, Christof
AU - Takei, Kohji
AU - Chen, Hong
AU - Ringstad, Niels
AU - Hudson, Amy
AU - Butler, Margaret Husta
AU - Salcini, Anna Elisabetta
AU - Di Fiore, Pier Paolo
AU - De Camilli, Pietro
N1 - Funding Information:
The results reported in this study provide new evidence supporting a role of synaptojanin 1 in endocytosis. We have shown that in nerve terminal membranes synaptojanin 1 is concentrated on endocytic intermediates. Its localization on clathrin-coated membrane invaginations was similar to that of amphiphysin 1 [20] and dynamin ( [21] and this study). On dynamin-coated tubules, synaptojanin 1 had a scattered distribution similar to that of amphiphysin 1 [20] . These data strongly support the hypothesis that the functions of dynamin and synaptojanin 1 are closely interrelated and that amphiphysin is a physiological binding partner for both proteins [10] . Synaptojanin 1 was also recruited to clathrin- and dynamin-coated intermediates when brain cytosol was incubated with fibroblastic membranes (our unpublished observations). Although our anti-synaptojanin 1 antibodies did not produce a detectable fluorescent signal outside the nervous system (probably due to the much lower concentration of synaptojanin 1 in non-neuronal tissue), synaptojanin 1 may play a conserved function in nerve terminals and non-neuronal cells. This possibility is supported by the biochemical detectability of both isoforms of synaptojanin 1 in a variety of tissues and by the presence of synaptojanin homologs in S. cerevisae [27] .
PY - 1997/12/15
Y1 - 1997/12/15
N2 - Synaptojanin 1 is an inositol 5-phosphatase with a putative role in clathrin-mediated endocytosis. Goal of this study was to provide new evidence for this hypothesis. We show that synaptojanin 1 is concentrated at clathrin-coated endocytic intermediates in nerve terminals. Furthermore, we report that synaptojanin-170, an alternatively spliced isoform of synaptojanin 1, binds Eps15, a clathrin coat-associated protein. Binding is mediated by the COOH-terminal region of synaptojanin-170 which we show here to be poorly conserved from rat to humans, but to contain in both species three asparagine-proline-phenylalanine (NPF) repeats. This motif has been found to be the core of the binding site for the EH domains of Eps15. Together with previous data, our results suggest that synaptojanin 1 can be recruited to clathrin-eoated pits via a multiplicity of interactions.
AB - Synaptojanin 1 is an inositol 5-phosphatase with a putative role in clathrin-mediated endocytosis. Goal of this study was to provide new evidence for this hypothesis. We show that synaptojanin 1 is concentrated at clathrin-coated endocytic intermediates in nerve terminals. Furthermore, we report that synaptojanin-170, an alternatively spliced isoform of synaptojanin 1, binds Eps15, a clathrin coat-associated protein. Binding is mediated by the COOH-terminal region of synaptojanin-170 which we show here to be poorly conserved from rat to humans, but to contain in both species three asparagine-proline-phenylalanine (NPF) repeats. This motif has been found to be the core of the binding site for the EH domains of Eps15. Together with previous data, our results suggest that synaptojanin 1 can be recruited to clathrin-eoated pits via a multiplicity of interactions.
KW - Dynamin
KW - Endocytosis
KW - Inositol 5-phosphatase
KW - Synapse
KW - Synaptic vesicle
UR - http://www.scopus.com/inward/record.url?scp=0031434562&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031434562&partnerID=8YFLogxK
U2 - 10.1016/S0014-5793(97)01451-8
DO - 10.1016/S0014-5793(97)01451-8
M3 - Article
C2 - 9428629
AN - SCOPUS:0031434562
SN - 0014-5793
VL - 419
SP - 175
EP - 180
JO - FEBS Letters
JF - FEBS Letters
IS - 2-3
ER -