Binds calcium. During feeding of the phloem sap, protein is injected into sieve tubes of rice plants. This process may suppress the sieve-element clogging and facilitate continuous ingestion from sieve tubes. Expressed in salivary glands where expression is strongest in type III cells in the posterior lobe of the principal glands (at protein level). Not expressed in midgut, Malpighian tubules or epidermis. Expressed on days 0-7 after adult emergence at roughly constant level (at protein level).