Metazoan granulins [ PUBMED:1542665 ] are a family of cysteine-rich peptides of about 6 Kd which may have multiple biological activity. A precursor protein (known as acrogranin) potentially encodes seven different forms of granulin (grnA to grnG) which are probably released by post-translational proteolytic processing. … expand

Metazoan granulins [ PUBMED:1542665 ] are a family of cysteine-rich peptides of about 6 Kd which may have multiple biological activity. A precursor protein (known as acrogranin) potentially encodes seven different forms of granulin (grnA to grnG) which are probably released by post-translational proteolytic processing. Granulins are evolutionary related to PMP-D1, a peptide extracted from the pars intercerebralis of migratory locusts [ PUBMED:1740125 ]. A schematic representation of the structure of a granulin is shown below:

 xxxCxxxxxCxxxxxCCxxxxxxxxCCxxxxxxCCxxxxxCCxxxxxCxxxxxxCx'C': conserved cysteine probably involved in a disulphide bond.

In plants a granulin domain is often associated with the C terminus of cysteine proteases belong to the MEROPS peptidase family C1, subfamily C1A (papain).