upload sketch to 2560 with usb-serial cable?

If I build my own "mega" board but leave off the USB adapter chip, can I just plug a USB-TTL cable into UART0 and upload a regular sketch to the 2560, assuming I loaded the bootloader already w/a dragon or somesuch over ISP?

permnoob:
If I build my own “mega” board but leave off the USB adapter chip, can I just plug a USB-TTL cable into UART0 and upload a regular sketch to the 2560, assuming I loaded the bootloader already w/a dragon or somesuch over ISP?

Yes.

that is the best news, thank you!