TY  - JOUR
AB  - Aggregation factors are the molecules responsible for species-specific cell adhesion in sponges. Here, we present the structure of the aggregation factor from the marine sponge Microciona prolifera, which constitutes the first description of a circular proteoglycan. We have analyzed chemically dissociated and enzymatically digested aggregation factor with atomic force microscopy, agarose gel electrophoresis, and Western blots using antibodies against the protein and carbohydrate moieties. Twenty units from each of two N-glycosylated proteins, MAFp3 and MAFp4, form the central ring and radiating arms, respectively, stabilized by a hyaluronidase-sensitive component. MAFp3 carries a 200-kDa glycan involved in homologous self-interactions between aggregation factor molecules, whereas MAFp4 carries a 6-kDa glycan that binds cell surface receptors. A 68-kDa lectin found in cell membranes of several sponge species binds the aggregation factor and its protein-free glycans, as well as chondroitin sulfate and hyaluronan. Here, we show that despite their lack of clear sequence homologies with other known proteoglycan structures, the protein and carbohydrate components of sponge aggregation factors assemble to form a supramolecular complex remarkably similar to classical proteoglycans.
DA  - 2000
DO  - 10.1006/jsbi.2000.4309
KW  - Hyaluronidase
KW  - Proteoglycan
KW  - Porifera
KW  - Cell adhesion
KW  - Atomic force microscope
LA  - eng
IS  - 2
M2  - 95
PY  - 2000
SN  - 1047-8477
SP  - 95-105
T2  - Journal of structural biology
TI  - Supramolecular structure of a new family of circular proteoglycans mediating cell adhesion in sponges
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-17732322
Y2  - 2024-11-22T04:55:13
ER  -