RT Journal Article ID 067afacf7e112b1a A1 de Koning, Pieter J. A. A1 Kummer, J. Alain A1 Bovenschen, Niels T1 Biology of Granzyme M: A Serine Protease with Unique Features JF Critical Reviews™ in Immunology JO CRI YR 2009 FD 2009-08-12 VO 29 IS 4 SP 307 OP 315 K1 granzyme K1 serine protease K1 expression K1 substrate K1 cell death K1 inhibitor K1 natural killer cell AB The granule-exocytosis pathway is the major mechanism for cytotoxic lymphocytes to kill tumor cells and virus-infected cells. Cytotoxic granules contain the pore-forming protein perforin and a set of structurally homologues serine proteases called granzymes. Perforin facilitates the entry of granzymes into a target cell, allowing these proteases to initiate distinct cell death routes by cleaving specific intracellular substrates. The family of granzymes consists of multiple members, of which granzyme A and granzyme B have been studied most extensively. Since the cloning of the granzyme M cDNA in the early 1990s, it has remained an "orphan" granzyme for many years and only during the past few years the interest in this protease has increased. Granzyme M appears to be a potent inducer of tumor cell death with morphological hallmarks that are unique among all granzymes. In this review, we summarize the characteristics of granzyme M that are currently known, including its cellular expression, substrate specificity, physiological functions, and inhibitors. PB Begell House LK https://www.dl.begellhouse.com/journals/2ff21abf44b19838,0104643e0471e3e3,067afacf7e112b1a.html