TY - JOUR

T1 - Galectin-3 guides intracellular trafficking of some human serotransferrin glycoforms

AU - Carlsson, Carl Michael

AU - Bengtson, Per

AU - Cucak, Helena

AU - Leffler, Hakon

PY - 2013/8/7

Y1 - 2013/8/7

N2 - Transferrin internalization via clathrin-mediated endocytosis and subsequent recycling after iron delivery has been extensively studied. Here we demonstrate a previously unrecognized parameter regulating this recycling -the binding of galectin-3 to particular glycoforms of transferrin. Two fractions of transferrin, separated by affinity chromatography based on their binding or not to galectin-3, are targeted to kinetically different endocytic pathways in HFL-1 cells expressing galectin-3 but not in SKBR3 cells lacking galectin-3; the SKBR3 cells, however can acquire the ability to target these transferrin glycoforms differently after preloading with exogenously added galectin-3. In all, this study provides the first evidence of a functional role for transferrin glycans, in intracellular trafficking after uptake. Moreover, the galectin-3 bound glycoform increased in cancer, suggesting a pathophysiological regulation. These are novel aspects of transferrin cell biology, which has previously considered only degree of iron loading, but not other forms of heterogeneity.

AB - Transferrin internalization via clathrin-mediated endocytosis and subsequent recycling after iron delivery has been extensively studied. Here we demonstrate a previously unrecognized parameter regulating this recycling -the binding of galectin-3 to particular glycoforms of transferrin. Two fractions of transferrin, separated by affinity chromatography based on their binding or not to galectin-3, are targeted to kinetically different endocytic pathways in HFL-1 cells expressing galectin-3 but not in SKBR3 cells lacking galectin-3; the SKBR3 cells, however can acquire the ability to target these transferrin glycoforms differently after preloading with exogenously added galectin-3. In all, this study provides the first evidence of a functional role for transferrin glycans, in intracellular trafficking after uptake. Moreover, the galectin-3 bound glycoform increased in cancer, suggesting a pathophysiological regulation. These are novel aspects of transferrin cell biology, which has previously considered only degree of iron loading, but not other forms of heterogeneity.

U2 - 10.1074/jbc.M113.487793

DO - 10.1074/jbc.M113.487793

M3 - Journal article

C2 - 23926108

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

ER -