Endocytic properties of the M-type 180-kDa receptor for secretory phospholipases A 2 (sPLA
2) were first investigated in rabbit myocytes that express it at high levels. Internalization of
the receptor was shown to be clathrin-coated pit-mediated, rapid (ke= 0.1 min-1), and ligand-
independent. The signal sequence for internalization was then identified upon transient and
stable expression of various receptor constructs with mutated cytoplasmic sequences.
Analysis of the internalization efficiency of the mutants suggested that the NSYY motif …