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Sulfate restriction induces hyposecretion of the adhesion proteoglycan and cell hypomotility associated with increased 35 SO 4 2− uptake and expression of a band 3 like protein in the marine sponge, Microciona prolifera
Author(s) -
Kuhns William J.,
Popescu Octavian,
Burger Max M.,
Misevic Gradimir
Publication year - 1995
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240570109
Subject(s) - chemistry , cell adhesion , sulfate , proteoglycan , cell , adhesion , biochemistry , extracellular matrix , organic chemistry
Sulfate is an important component relating to normal proteoglycan secretion and normal motility in the marine sponge, Microciona prolifera . The following alterations were observed in sponge cells when sulfate free artificial sea water was used as the suspension medium: (1) impairment of aggregation, (2) loss of cell movements, (3) a marked reduction in the secretion of the adhesion proteoglycan (AP). Reversal of this effect occurred if sulfate depleted cells were again rotated in sulfate containing artificial sea water. Motility and reaggregation of sulfate deprived cells could be completely restored by purified AP, but only if cells were first pre‐conditioned in normal sea water. Comparisons of 35 SO 4 2− uptake between normal and sulfate deprived cells which had been treated to reduce preformed secretions showed a marked increase in 35 SO 4 2− uptake and incorporation which could be greatly augmented in the presence of Ca 2+ /Mg 2+ . Excessive retention of AP in sulfate starved cells demonstrated by immunostaining suggested that AP secretion and cellular motility may be controlled by a sulfate dependent secretogogue or that undersulfated AP itself had developed a secretory defect. SDS‐PAGE of Triton treated cellular extracts demonstrated a 116 kDa 35 SO 4 2− sulfated band which co‐migrated with AP, but only in extracts derived from sulfate starved cells. Western blots prepared from such extracts incubated in the presence of a monoclonal anti‐band 3 antibody demonstrated labelling of a single 97 kDa band only in material from sulfate deprived cells. The absence of this component in normal cell extracts indicated that this protein may be involved in facilitated sulfate transport. This study lends support to a heretofore unrecognized role for sulfate in cell motility and secretion.