Dynamins, phosphoproteins with intrinsic GTPase activities, play an important role during early endocytosis. The GTPase activity is stimulated in vitro by microtubules, SH3 domain containing-proteins, and Protein Kinase (PKC)- mediated phosphorylation. Although highly related, dynamins are differentially expressed in an organism. For instance, dynamin I is found only in the nervous system, dynamin II is ubiquitously expressed, and dynamin III is located in lung, testis and brain. Due to four alternative splicing products for each of the dynamins, the dynamin family contains at least 12 different members. The Dynamin Like Protein-1 (DLP1) is a new member of the dynamin family of proteins. DLP1 (also known as DVLP) is widely expressed as two alternatively spliced products, each with different tissue expression patterns. The larger product is about 84 kDa and reportedly found only in the brain, whereas the 79 kDa product is ubiquitously expressed. Unlike dynamins I-III which co-localize with endocytotic vesicles, DLP1 is found aligned with microtubules and with the endoplasmic reticulum, suggesting a secretory function for this novel protein.